OSA's Digital Library

Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 20, Iss. 11 — May. 21, 2012
  • pp: 12004–12013
« Show journal navigation

Fiber-based source for multiplex-CARS microscopy based on degenerate four-wave mixing

Thomas Gottschall, Martin Baumgartl, Aude Sagnier, Jan Rothhardt, Cesar Jauregui, Jens Limpert, and Andreas Tünnermann  »View Author Affiliations


Optics Express, Vol. 20, Issue 11, pp. 12004-12013 (2012)
http://dx.doi.org/10.1364/OE.20.012004


View Full Text Article

Acrobat PDF (2020 KB)





Browse Journals / Lookup Meetings

Browse by Journal and Year


   


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools

Share
Citations

Abstract

We present a fiber-based laser source for multiplex coherent anti-Stokes Raman scattering (CARS) microscopy. This source is very compact and potentially alignment-free. The corresponding pump and Stokes pulses for the CARS process are generated by degenerate four-wave mixing (FWM) in photonic-crystal fibers. In addition, an ytterbium-doped fiber laser emitting spectrally narrow 100 ps pulses at 1035 nm wavelength serves as pump for the FWM frequency conversion. The FWM process delivers narrow-band pulses at 648 nm and drives a continuum-like spectrum ranging from 700 to 820 nm. With the presented source vibrational resonances with energies between 1200 cm−1 and 3200 cm−1 can be accessed with a resolution of 10 cm−1. Additionally, the temporal characteristics of the FWM output have been investigated by a cross-correlation setup, revealing the suitability of the emitted pulses for CARS microscopy. This work marks a significant step towards a simple and powerful all-fiber, maintenance-free multiplex-CARS source for real-world applications outside a laboratory environment.

© 2012 OSA

1. Introduction

Coherent anti-Stokes Raman scattering (CARS) microscopy is a potent spectroscopic technique for probing vibrational resonances without the need for bio-hazardous contrast materials [1

1. A. Zumbusch, G. R. Holtom, and X. S. Xie, “Three-dimensional vibrational imaging by coherent anti-Stokes Raman scattering,” Phys. Rev. Lett. 82(20), 4142–4145 (1999). [CrossRef]

]. Using CARS provides a better resolution and results in lower absorption than direct spectroscopy in the mid-IR. Coupled with high-sensitivity scanning, it may open the way for spectrally resolved real-time in vivo images of living tissue, e.g. during surgery [2

2. T. Meyer, N. Bergner, C. Bielecki, C. Krafft, D. Akimov, B. F. M. Romeike, R. Reichart, R. Kalff, B. Dietzek, and J. Popp, “Nonlinear microscopy, infrared, and Raman microspectroscopy for brain tumor analysis,” J. Biomed. Opt. 16(2), 021113 (2011). [CrossRef] [PubMed]

].

The CARS process is based on a four-photon interaction. If the frequency difference of the pump and Stokes laser matches a vibrational frequency, simultaneous illumination selectively populates this level and further probe photons are inelastically scattered off this vibrational state generating emission at the CARS frequency (ωCARS = ωprobe + ωPump – ωStokes, angular frequency). The ensemble is excited in phase, thus the generation of the CARS signal is coherent to the probe laser. Since the emitted photons have the highest frequency in the process, it can be easily filtered and detected. The intensity of the CARS signal depends on the product of the intensities of the pump, Stokes and probe signals (ICARS~Iprobe·Ipump·Istokes). Due to this nonlinear interaction only a small focal volume contributes to the CARS signal, providing CARS with its 3-dimensional sectioning capabilities.

Due to the nonlinearity of the process and an anticipated application in the life sciences, a laser source for CARS should possess the following features:

  • Synchronized wavelength channels ωPump and ωStokes corresponding to the vibrational energy level (ωvib = ωPump – ωStokes) to be probed
  • Wavelengths in the NIR to minimize the absorption losses in tissue
  • High intensities to generate a detectable CARS signal
  • Narrow bandwidth probe beam for a high-resolution CARS signal (pulse durations in the picosecond range)
  • MHz repetition rates to enable high scan rates when used in laser scanning microscopes
  • Matched linear polarization states of the signals

Detecting more than one resonance to identify different substances without changing the laser setup is an additional desirable but challenging feature. This so-called multiplex-CARS (MCARS) demands an increased spectral bandwidth of the pump and/or Stokes laser [3

3. M. Müller and J. M. Schins, “Imaging the thermodynamic state of lipid membranges with multiplex CARS microscopy,” J. Phys. Chem. B 106(14), 3715–3723 (2002). [CrossRef]

]. In contrast, the probe spectrum has to be spectrally narrow to obtain a high spectral resolution of the CARS signal and so to be able to differentiate between adjacent molecular resonances. This creates a high demand on the CARS laser source.

Today, typical laser sources for CARS employ two actively synchronized mode-locked solid-state lasers or one solid-state laser where the other wavelength is generated via parametric frequency conversion (optical parametric oscillators or amplifiers) in bulk crystals. Therefore, the pulses are inherently synchronized to each other. These bulk systems are very versatile and have nearly ideal parameters for the CARS process. Unfortunately, these sources are quite large, expensive and require trained staff to be maintained and aligned. However, in order to allow for a wider spectrum of researchers to have access to this technology and to enable the medical community to use CARS on a day-to-day basis as a reliable diagnosis/analysis tool, there is a great demand for an easy-to-use, compact and, at the same time, inexpensive and reliable solution.

Fiber lasers can potentially meet those requirements. Through design and integration of the laser system with fiber-based components, the need for robustness, compactness and cost efficiency can be fulfilled. On top of that, new features and possibilities constantly arise from novel fiber designs and concepts [4

4. P. Russell, “Photonic crystal fibers,” Science 299(5605), 358–362 (2003). [CrossRef] [PubMed]

]. Features like soliton self-frequency shift (SSFS) [5

5. J. P. Gordon, “Theory of the soliton self-frequency shift,” Opt. Lett. 11(10), 662–664 (1986). [CrossRef] [PubMed]

,6

6. F. M. Mitschke and L. F. Mollenauer, “Discovery of the soliton self-frequency shift,” Opt. Lett. 11(10), 659–661 (1986). [CrossRef] [PubMed]

], supercontinuum generation (SC) [7

7. R. R. Alfano, ed., The Supercontinuum Laser Source (Springer-Verlag, 1989).

] and four wave mixing [8

8. W. Wadsworth, N. Joly, J. Knight, T. Birks, F. Biancalana, and P. Russell, “ Supercontinuum and four-wave mixing with Q-switched pulses in endlessly single-mode photonic crystal fibres,” Opt. Express 12(2), 299–309 (2004). [CrossRef] [PubMed]

10

10. L. Lavoute, J. C. Knight, P. Dupriez, and W. J. Wadsworth, “High power red and near-IR generation using four wave mixing in all integrated fibre laser systems,” Opt. Express 18(15), 16193–16205 (2010). [CrossRef] [PubMed]

] offer frequency conversion schemes unique to fibers. Frequency conversion methods like the optical parametric oscillator rely on free-space propagation with the well-known disadvantages [11

11. K. Kieu, B. G. Saar, G. R. Holtom, X. S. Xie, and F. W. Wise, “High-power picosecond fiber source for coherent Raman microscopy,” Opt. Lett. 34(13), 2051–2053 (2009). [CrossRef] [PubMed]

].

Without post-processing, the spectra of SSFS are broad, hence reducing the spectral resolution and the contrast between the resonance and the non-resonant background in the CARS signal. SC and SSFS are usually driven by pulses with durations in the femtosecond range [12

12. G. P. Agrawal, Nonlinear Fiber Optics (Academic, 2001).

], whereas usually picosecond pulses are preferable for CARS. To circumvent this issue, spectral compression techniques have been used to convert supercontinuum radiation to picosecond durations via second harmonic generation in a periodically poled lithium niobate (PPLN) crystal [13

13. M. Marangoni, A. Gambetta, C. Manzoni, V. Kumar, R. Ramponi, and G. Cerullo, “Fiber-format CARS spectroscopy by spectral compression of femtosecond pulses from a single laser oscillator,” Opt. Lett. 34(21), 3262–3264 (2009). [CrossRef] [PubMed]

]. Very recently, a photonic-crystal fiber (PCFs) has been employed to generate the wavelength pair required for CARS by degenerate FWM [13

13. M. Marangoni, A. Gambetta, C. Manzoni, V. Kumar, R. Ramponi, and G. Cerullo, “Fiber-format CARS spectroscopy by spectral compression of femtosecond pulses from a single laser oscillator,” Opt. Lett. 34(21), 3262–3264 (2009). [CrossRef] [PubMed]

]. By tuning the FWM-pump wavelength by just a few nanometers, a scan over a single vibrational resonance in toluene has been demonstrated in an all-fiber setup, in which both the pump and Stokes signals were delivered from a single fiber end.

The manuscript is organized as follows: Section 2 is devoted to presenting the experimental setup. Section 3 discusses the fiber based frequency conversion approach and its spectral and temporal characterization. Finally, section 4 features the experimental results achieved with this source including its application to multiplex-CARS.

2. The ytterbium-doped fiber pump laser system

In order to generate sufficient peak power to drive both fiber-based frequency conversion processes at MHz repetition rates, a master oscillator power amplifier concept has been realized. A passively mode-locked femtosecond all-fiber oscillator serves as seed laser, followed by an acousto-optic modulator (AOM) to reduce the pulse repetition rate. A key component is a narrow-band fiber Bragg grating (FBG) acting as spectral filter, which determines the final pulse duration of the pump source [16

16. J. Rothhardt, S. Hädrich, J. Limpert, and A. Tünnermann, “80 kHz repetition rate high power fiber amplifier flat-top pulse pumped OPCPA based on BIB3O6,” Opt. Express 17(4), 2508–2517 (2009). [CrossRef] [PubMed]

]. We have chosen a pulse duration of 100 ps as it falls into an optimal range for fiber FWM based frequency conversion [9

9. D. Nodop, C. Jauregui, D. Schimpf, J. Limpert, and A. Tünnermann, “Efficient high-power generation of visible and mid-infrared light by degenerate four-wave-mixing in a large-mode-area photonic-crystal fiber,” Opt. Lett. 34(22), 3499–3501 (2009). [CrossRef] [PubMed]

]. The system, as seen in Fig. 1
Fig. 1 Schematic setup of the fiber laser system employed to drive two four-wave-mixing processes. ISO: optical isolator, AOM: acousto-optic modulator, PM FBG: polarization-maintaining fiber bragg grating, HWP: half-wave plate, CIRC: circulator.
, consists of spliced polarization-maintaining (PM) fibers up to the third amplifier and it is, therefore, alignment-free.

3. In-fiber frequency conversion by degenerate four-wave-mixing (DFWM)

As mentioned above, a pulse duration in the order of 100 ps has been chosen in the described experiments. This pulse duration appears as a good compromise to minimize the effects of self-phase modulation (SPM), which is dominant at shorter pulse durations and Raman/Brillion scattering, known to become severe at longer pulse durations [12

12. G. P. Agrawal, Nonlinear Fiber Optics (Academic, 2001).

]. Since the spectral resolution of the CARS signal depends on the spectral width of the probe, it is also favorable to use narrow band ps-pulses, if their peak power is high enough. Due to the dispersion in the fiber, which can be tailored by means of the photonic structure, different phase-matched wavelength pairs can be expected in different PCFs. Moreover, the slope of the mismatch at the phase-matched frequencies can be different, thus, resulting in different FWM-gain bandwidths. Figure 3
Fig. 3 The spectral characteristics of the parametric gain in different LMA-PCF fibers when pumped with linear polarized 1036 nm radiation with 20 kW of peak power. The table summarizes the central FWM-signal wavelengths and, furthermore, the group velocity difference between the signal and the pump pulse while propagating in the specific fiber.
summarizes the properties of the considered PCFs (nomenclature by NKT photonics, RD5: custom design) as well as their expected phase-matched FWM-signal wavelengths. Furthermore, the calculated spectral characteristics of the parametric gain in those fibers are shown. The simulation was performed by using the poor man’s approach [18

18. J. Riishede, N. A. Mortensen, and J. Lægsgaard, “A ‘poor man’s approach’ to modelling micro-structured optical fibres,” J. Opt. A, Pure Appl. Opt. 5(5), 534–538 (2003). [CrossRef]

] to calculate the effective index of the fiber. Afterwards the phase matching curve with the specific pitch Λ and hole diameter d of the fiber was calculated.

A tradeoff has to be met for the optimal PCF to create the pump radiation for CARS. First, the fiber should possess a narrow gain bandwidth, on the other hand, the generated wavelength should not be too close to the near-infrared spectral region to avoid a detrimental increase of the pump/probe bandwidth. In this case the contrast of the CARS signal to the non-resonant FWM signal will decrease if the Raman signal linewidth is surpassed.

In [9

9. D. Nodop, C. Jauregui, D. Schimpf, J. Limpert, and A. Tünnermann, “Efficient high-power generation of visible and mid-infrared light by degenerate four-wave-mixing in a large-mode-area photonic-crystal fiber,” Opt. Lett. 34(22), 3499–3501 (2009). [CrossRef] [PubMed]

] it has been shown that the temporal pulse shape becomes more and more complex due to the occurrence of successive back-conversion processes in longer fiber sections or at higher input peak powers.

On the other hand, using a short conversion fiber or moderate pulse energies, clean signal pulses can be generated, at the price of sacrificing conversion efficiency. These signal pulses can be significantly shorter than the pump pulses, as the conversion is only efficient around the pulse peak. Figure 5b
Fig. 5 (a) Trace-by-trace normalized cross-correlation time traces of the pump pulses of the FWM process (at 1036nm) with increasing output energies, showing the depletion of the pump pulses. (b) Trace-by-trace normalized time traces of the degenerated FWM signal (at 648 nm) with increasing output energies, showing the evolution caused by the temporal walk-off between the driving pump pulses and the converted signal pulses.
illustrates this behavior by showing cross-correlation measurements of the FWM-pump and –signal pulses at different energy levels. Due to a strong walk-off between the pump pulse and the created signal pulse (see the table in Fig. 5b) a shift of the conversion to the trailing edge of the pump pulse is revealed. According to the group velocity difference of the pulses involved during the FWM process in the LMA-8 fiber the walk-off is as high as 35 ps/m. Depending on this value and the input pulse duration of the pump, a shortening of the signal pulse duration is possible. At 1.8 µJ of pump energy the signal pulses have a duration of 65 ps at 320 nJ of pulse energy which translates to a peak power of 5.5 kW.

To create the broadband multiplex-CARS-Stokes wave, 1m of PCF with a hole-to-hole distance of Λ = 4 µm and a hole diameter of d = 2 µm, referred to as RD5 (PCF 2), has been employed. A narrow-band conversion to 714 nm is obtained at 0.8 µJ. Above this energy a Raman-seeded parametric conversion shifts a portion of the energy to longer wavelengths filling the spectral gap between the pump wavelength at 1036 nm and the phase-matched FWM-signal wavelength. The continuum (see Fig. 6
Fig. 6 SC generation based on FWM in 1m RD5 fiber as a function of input pulse energy.
) has a high spectral energy density of 4 nJ/nm (at 800 nm wavelength, 2.4 µJ FWM-pump energy), which corresponds to a peak power density of >40 W/nm assuming a pulse duration below 100 ps in this spectral band. This assumption can be done since the conversion mechanisms in play are on a much shorter time scale than the pulse length.

4. Application of the fiber source to CARS spectroscopy

To demonstrate the multiplex CARS capabilities of the setup a preliminary not optimized experiment was conducted. A CARS spectrum was measured by placing a sample of toluene into the overlapped and focused beams of the pump/probe and Stokes signal (Fig. 7
Fig. 7 Super continuum generation based on FWM as a function of the overall output pulse energy. HR 1036 nm: highly reflective mirror at 1036 nm, LP 650 nm: long pass filter at 650nm, SP 650 nm/SP 600 nm: short pass filter at 650 nm/600 nm, OSA: optical spectrum analyzer.
). Highly reflective (HR) mirrors in both branches filtered the residual pump from the frequencies generated via FWM.

A HR mirror at 650 nm wavelength was used to overlap the pump/probe beam with the Stokes beam. A long-pass filter at 650 nm removes undesired frequencies originating from the SC generation. A delay stage was used to overlap the pulses in time. Additionally, both beams were focused with 10 × to ensure that every frequency component of the SC overlaps with the pump/probe beam in the focus where the test sample was placed. The generated CARS signal was selected by two short-pass filters at 650 nm and 600 nm. The CARS spectrum ranged from 540 to 605 nm corresponding to a frequency difference between pump and Stokes from 1200 cm−1 to 3200 cm−1, as depicted in Fig. 8
Fig. 8 Measured CARS spectrum of toluene with identified resonances.
. The experiment was performed at 0.5 MHz using an overall average power in the super-continuum of 1.7 W and 150 mW of average pump power at 648 nm. The CARS signal was then filtered and focused into a multimode fiber to deliver the light to an optical spectrum analyzer.

The poor contrast of the CARS spectrum is due to the presence of nonresonant background radiation. Nevertheless the aromatic C-H vibrational resonances near 3000 cm−1 generate a high response and possess a good contrast, while weaker resonances in the so called fingerprint region show a reduced visibility. Thus, in order to detect certain substances in biological samples it is necessary to apply numerical algorithms to extract the composition of the specimen from the MCARS spectrum (e.g. Kramers-Kronig or maximum entropy [19

19. E. M. Vartiainen, H. A. Rinia, M. Müller, and M. Bonn, “Direct extraction of Raman line-shapes from congested CARS spectra,” Opt. Express 14(8), 3622–3630 (2006). [CrossRef] [PubMed]

,20

20. Y. Liu, Y. J. Lee, and M. T. Cicerone, “Broadband CARS spectral phase retrieval using a time-domain Kramers-Kronig transform,” Opt. Lett. 34(9), 1363–1365 (2009). [CrossRef] [PubMed]

]). To further improve the capabilities of the CARS-source further and to increase the visibility of the Raman resonances different measures may be taken. Other samples of acetone and mixtures of acetone and toluene were measured showing the main resonances of both substances in the region of 3000cm−1. These results are not presented in this paper since these measurements were taken with a different conversion fiber to create the Stokes wavelength.

To address smaller molecular vibrational energies and to cover the whole fingerprint region, a different combination of fibers could be necessary. The first possibility is to use two LMA-8 fibers. One to create the narrow band pump/probe radiation and the other one for supercontiuum generation ranging from 648 nm to >800 nm. This would require much more pump energy and/or fiber lengths in the supercontinuum part to achieve sufficient broadening. Another possibility is to use two LMA-5 fibers in the same configuration which would relax the demand for pump peak power but also decrease the spectral resolution of the CARS process since the probe pulses would become wider. A custom LMA fiber design with a DFWM phase matching wavelength at 690 nm (pumped with 1036 nm radiation) would enable excitation of molecular vibrational energies from 940 cm−1 to 3200 cm−1. To reduce the influence of the nonresonant background radiation while maintaining the multiplex capabilities of the source, the pump and Stokes beams could be created at longer wavelengths. Additionally, in order to maintain a reasonable spectral resolution a spectrally narrow probe beam could be generated by seeding the FWM process by a narrowband diode laser source located spectrally at the high frequency gain peak of the fiber [21

21. P. J. Mosley, S. A. Bateman, L. Lavoute, and W. J. Wadsworth, “Low-noise, high-brightness, tunable source of picosecond pulsed light in the near-infrared and visible,” Opt. Express 19(25), 25337–25345 (2011). [CrossRef] [PubMed]

]. Combining the seeding concept with LMA-5 fibers for continuum and pump generation, a multiplex-CARS source covering the whole resonance spectrum below 3200 cm−1 could be realized with high spectral resolution.

5. Conclusion

To the best of our knowledge, we have demonstrated a multiplex-CARS source based on parametric in-fiber frequency conversion by four wave mixing for the first time. We were able to use the same fiber concept with different parameters to create an intense, narrowband pump and probe beam to ensure very high spectral resolution (below 10 cm−1) and a smooth continuum with very high spectral densities. FWM induced supercontinuum generation allows for a controlled energy conversion through the design parameters of the PCF enabling a high power density supercontinuum.

An Yb-fiber laser generates 106 ps pulses with 14 µJ of pulse energy at 1036 nm, 0.5 MHz, which are then frequency converted in a PCF to obtain high-power, passively synchronized CARS pump pulses with a duration of 65 ps. The generated wavelength pair of 648 nm and 700-820 nm was used to probe vibrational resonances of toluene between 1200 and 3200 cm−1.

In contrast to other fiber based frequency conversion concepts on the basis of supercontinuum generation or Raman-scattering based soliton shifts, FWM gives the opportunity for narrowband frequency conversion to shorter wavelengths. Using the emission of FWM induced SC for the CARS Stokes, a multiplex CARS source with synchronized pump, Stokes and probe beams and high spectral resolution of ~10 cm−1 has been created.

This unique light source works in the same wavelength range as titanium-sapphire based systems but with superior stability and usability. Furthermore, the laboratory setup of the current system has a footprint of only 1 m2 and consists of commercially available fiber components, securing robust and low-cost implementation. Replacing the fs- by a ps-oscillator with a lower repetition rate would simplify the system even further to a point where only one amplifier and the conversion PCFs are required. As an alternative, a high-repetition-rate fiber-coupled microchip laser [22

22. A. Steinmetz, D. Nodop, A. Martin, J. Limpert, and A. Tünnermann, “Reduction of timing jitter in passively Q-switched microchip lasers using self-injection seeding,” Opt. Lett. 35(17), 2885–2887 (2010). [CrossRef] [PubMed]

] might be employed as a seed source. Hence, the presented approach represents a true alternative to much bulkier systems and it has the potential to achieve a wider use of CARS microscopy technology in real-world applications.

Acknowledgments

This work was partly supported by the German Federal Ministry of Education and Research (BMBF) under contract 13N10773. M. Baumgartl acknowledges support from the Carl-Zeiss-Stiftung. J. Rothhardt acknowledges support from the German Academic Exchange Service (DAAD). The authors like to thank T. V. Andersen from NKT Photonics for providing the RD photonic-crystal fibers and Tobias Meyer from the IPHT Jena for helpful dicussions.

References and links

1.

A. Zumbusch, G. R. Holtom, and X. S. Xie, “Three-dimensional vibrational imaging by coherent anti-Stokes Raman scattering,” Phys. Rev. Lett. 82(20), 4142–4145 (1999). [CrossRef]

2.

T. Meyer, N. Bergner, C. Bielecki, C. Krafft, D. Akimov, B. F. M. Romeike, R. Reichart, R. Kalff, B. Dietzek, and J. Popp, “Nonlinear microscopy, infrared, and Raman microspectroscopy for brain tumor analysis,” J. Biomed. Opt. 16(2), 021113 (2011). [CrossRef] [PubMed]

3.

M. Müller and J. M. Schins, “Imaging the thermodynamic state of lipid membranges with multiplex CARS microscopy,” J. Phys. Chem. B 106(14), 3715–3723 (2002). [CrossRef]

4.

P. Russell, “Photonic crystal fibers,” Science 299(5605), 358–362 (2003). [CrossRef] [PubMed]

5.

J. P. Gordon, “Theory of the soliton self-frequency shift,” Opt. Lett. 11(10), 662–664 (1986). [CrossRef] [PubMed]

6.

F. M. Mitschke and L. F. Mollenauer, “Discovery of the soliton self-frequency shift,” Opt. Lett. 11(10), 659–661 (1986). [CrossRef] [PubMed]

7.

R. R. Alfano, ed., The Supercontinuum Laser Source (Springer-Verlag, 1989).

8.

W. Wadsworth, N. Joly, J. Knight, T. Birks, F. Biancalana, and P. Russell, “ Supercontinuum and four-wave mixing with Q-switched pulses in endlessly single-mode photonic crystal fibres,” Opt. Express 12(2), 299–309 (2004). [CrossRef] [PubMed]

9.

D. Nodop, C. Jauregui, D. Schimpf, J. Limpert, and A. Tünnermann, “Efficient high-power generation of visible and mid-infrared light by degenerate four-wave-mixing in a large-mode-area photonic-crystal fiber,” Opt. Lett. 34(22), 3499–3501 (2009). [CrossRef] [PubMed]

10.

L. Lavoute, J. C. Knight, P. Dupriez, and W. J. Wadsworth, “High power red and near-IR generation using four wave mixing in all integrated fibre laser systems,” Opt. Express 18(15), 16193–16205 (2010). [CrossRef] [PubMed]

11.

K. Kieu, B. G. Saar, G. R. Holtom, X. S. Xie, and F. W. Wise, “High-power picosecond fiber source for coherent Raman microscopy,” Opt. Lett. 34(13), 2051–2053 (2009). [CrossRef] [PubMed]

12.

G. P. Agrawal, Nonlinear Fiber Optics (Academic, 2001).

13.

M. Marangoni, A. Gambetta, C. Manzoni, V. Kumar, R. Ramponi, and G. Cerullo, “Fiber-format CARS spectroscopy by spectral compression of femtosecond pulses from a single laser oscillator,” Opt. Lett. 34(21), 3262–3264 (2009). [CrossRef] [PubMed]

14.

M. Baumgartl, M. Chemnitz, C. Jauregui, T. Meyer, B. Dietzek, J. Popp, J. Limpert, and A. Tünnermann, “All-fiber laser source for CARS microscopy based on fiber optical parametric frequency conversion,” Opt. Express 20(4), 4484–4493 (2012). [CrossRef] [PubMed]

15.

S. Coen, A. H. L. Chau, R. Leonhardt, J. D. Harvey, J. C. Knight, W. J. Wadsworth, and P. St. J. Russell, “White-light supercontinuum generation with 60-ps pump pulses in a photonic crystal fiber,” Opt. Lett. 26(17), 1356–1358 (2001). [CrossRef] [PubMed]

16.

J. Rothhardt, S. Hädrich, J. Limpert, and A. Tünnermann, “80 kHz repetition rate high power fiber amplifier flat-top pulse pumped OPCPA based on BIB3O6,” Opt. Express 17(4), 2508–2517 (2009). [CrossRef] [PubMed]

17.

B. Ortaς, M. Plötner, T. Schreiber, J. Limpert, and A. Tünnermann, “Experimental and numerical study of pulse dynamics in positive net-cavity dispersion modelocked Yb-doped fiber lasers,” Opt. Express 15(23), 15595–15602 (2007). [CrossRef] [PubMed]

18.

J. Riishede, N. A. Mortensen, and J. Lægsgaard, “A ‘poor man’s approach’ to modelling micro-structured optical fibres,” J. Opt. A, Pure Appl. Opt. 5(5), 534–538 (2003). [CrossRef]

19.

E. M. Vartiainen, H. A. Rinia, M. Müller, and M. Bonn, “Direct extraction of Raman line-shapes from congested CARS spectra,” Opt. Express 14(8), 3622–3630 (2006). [CrossRef] [PubMed]

20.

Y. Liu, Y. J. Lee, and M. T. Cicerone, “Broadband CARS spectral phase retrieval using a time-domain Kramers-Kronig transform,” Opt. Lett. 34(9), 1363–1365 (2009). [CrossRef] [PubMed]

21.

P. J. Mosley, S. A. Bateman, L. Lavoute, and W. J. Wadsworth, “Low-noise, high-brightness, tunable source of picosecond pulsed light in the near-infrared and visible,” Opt. Express 19(25), 25337–25345 (2011). [CrossRef] [PubMed]

22.

A. Steinmetz, D. Nodop, A. Martin, J. Limpert, and A. Tünnermann, “Reduction of timing jitter in passively Q-switched microchip lasers using self-injection seeding,” Opt. Lett. 35(17), 2885–2887 (2010). [CrossRef] [PubMed]

OCIS Codes
(060.4370) Fiber optics and optical communications : Nonlinear optics, fibers
(140.7300) Lasers and laser optics : Visible lasers
(170.3880) Medical optics and biotechnology : Medical and biological imaging
(190.4370) Nonlinear optics : Nonlinear optics, fibers
(190.4380) Nonlinear optics : Nonlinear optics, four-wave mixing
(300.6230) Spectroscopy : Spectroscopy, coherent anti-Stokes Raman scattering
(180.4315) Microscopy : Nonlinear microscopy

ToC Category:
Microscopy

History
Original Manuscript: February 22, 2012
Revised Manuscript: April 3, 2012
Manuscript Accepted: April 8, 2012
Published: May 11, 2012

Virtual Issues
Vol. 7, Iss. 7 Virtual Journal for Biomedical Optics

Citation
Thomas Gottschall, Martin Baumgartl, Aude Sagnier, Jan Rothhardt, Cesar Jauregui, Jens Limpert, and Andreas Tünnermann, "Fiber-based source for multiplex-CARS microscopy based on degenerate four-wave mixing," Opt. Express 20, 12004-12013 (2012)
http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-20-11-12004


Sort:  Author  |  Year  |  Journal  |  Reset  

References

  1. A. Zumbusch, G. R. Holtom, and X. S. Xie, “Three-dimensional vibrational imaging by coherent anti-Stokes Raman scattering,” Phys. Rev. Lett.82(20), 4142–4145 (1999). [CrossRef]
  2. T. Meyer, N. Bergner, C. Bielecki, C. Krafft, D. Akimov, B. F. M. Romeike, R. Reichart, R. Kalff, B. Dietzek, and J. Popp, “Nonlinear microscopy, infrared, and Raman microspectroscopy for brain tumor analysis,” J. Biomed. Opt.16(2), 021113 (2011). [CrossRef] [PubMed]
  3. M. Müller and J. M. Schins, “Imaging the thermodynamic state of lipid membranges with multiplex CARS microscopy,” J. Phys. Chem. B106(14), 3715–3723 (2002). [CrossRef]
  4. P. Russell, “Photonic crystal fibers,” Science299(5605), 358–362 (2003). [CrossRef] [PubMed]
  5. J. P. Gordon, “Theory of the soliton self-frequency shift,” Opt. Lett.11(10), 662–664 (1986). [CrossRef] [PubMed]
  6. F. M. Mitschke and L. F. Mollenauer, “Discovery of the soliton self-frequency shift,” Opt. Lett.11(10), 659–661 (1986). [CrossRef] [PubMed]
  7. R. R. Alfano, ed., The Supercontinuum Laser Source (Springer-Verlag, 1989).
  8. W. Wadsworth, N. Joly, J. Knight, T. Birks, F. Biancalana, and P. Russell, “ Supercontinuum and four-wave mixing with Q-switched pulses in endlessly single-mode photonic crystal fibres,” Opt. Express12(2), 299–309 (2004). [CrossRef] [PubMed]
  9. D. Nodop, C. Jauregui, D. Schimpf, J. Limpert, and A. Tünnermann, “Efficient high-power generation of visible and mid-infrared light by degenerate four-wave-mixing in a large-mode-area photonic-crystal fiber,” Opt. Lett.34(22), 3499–3501 (2009). [CrossRef] [PubMed]
  10. L. Lavoute, J. C. Knight, P. Dupriez, and W. J. Wadsworth, “High power red and near-IR generation using four wave mixing in all integrated fibre laser systems,” Opt. Express18(15), 16193–16205 (2010). [CrossRef] [PubMed]
  11. K. Kieu, B. G. Saar, G. R. Holtom, X. S. Xie, and F. W. Wise, “High-power picosecond fiber source for coherent Raman microscopy,” Opt. Lett.34(13), 2051–2053 (2009). [CrossRef] [PubMed]
  12. G. P. Agrawal, Nonlinear Fiber Optics (Academic, 2001).
  13. M. Marangoni, A. Gambetta, C. Manzoni, V. Kumar, R. Ramponi, and G. Cerullo, “Fiber-format CARS spectroscopy by spectral compression of femtosecond pulses from a single laser oscillator,” Opt. Lett.34(21), 3262–3264 (2009). [CrossRef] [PubMed]
  14. M. Baumgartl, M. Chemnitz, C. Jauregui, T. Meyer, B. Dietzek, J. Popp, J. Limpert, and A. Tünnermann, “All-fiber laser source for CARS microscopy based on fiber optical parametric frequency conversion,” Opt. Express20(4), 4484–4493 (2012). [CrossRef] [PubMed]
  15. S. Coen, A. H. L. Chau, R. Leonhardt, J. D. Harvey, J. C. Knight, W. J. Wadsworth, and P. St. J. Russell, “White-light supercontinuum generation with 60-ps pump pulses in a photonic crystal fiber,” Opt. Lett.26(17), 1356–1358 (2001). [CrossRef] [PubMed]
  16. J. Rothhardt, S. Hädrich, J. Limpert, and A. Tünnermann, “80 kHz repetition rate high power fiber amplifier flat-top pulse pumped OPCPA based on BIB3O6,” Opt. Express17(4), 2508–2517 (2009). [CrossRef] [PubMed]
  17. B. Ortaς, M. Plötner, T. Schreiber, J. Limpert, and A. Tünnermann, “Experimental and numerical study of pulse dynamics in positive net-cavity dispersion modelocked Yb-doped fiber lasers,” Opt. Express15(23), 15595–15602 (2007). [CrossRef] [PubMed]
  18. J. Riishede, N. A. Mortensen, and J. Lægsgaard, “A ‘poor man’s approach’ to modelling micro-structured optical fibres,” J. Opt. A, Pure Appl. Opt.5(5), 534–538 (2003). [CrossRef]
  19. E. M. Vartiainen, H. A. Rinia, M. Müller, and M. Bonn, “Direct extraction of Raman line-shapes from congested CARS spectra,” Opt. Express14(8), 3622–3630 (2006). [CrossRef] [PubMed]
  20. Y. Liu, Y. J. Lee, and M. T. Cicerone, “Broadband CARS spectral phase retrieval using a time-domain Kramers-Kronig transform,” Opt. Lett.34(9), 1363–1365 (2009). [CrossRef] [PubMed]
  21. P. J. Mosley, S. A. Bateman, L. Lavoute, and W. J. Wadsworth, “Low-noise, high-brightness, tunable source of picosecond pulsed light in the near-infrared and visible,” Opt. Express19(25), 25337–25345 (2011). [CrossRef] [PubMed]
  22. A. Steinmetz, D. Nodop, A. Martin, J. Limpert, and A. Tünnermann, “Reduction of timing jitter in passively Q-switched microchip lasers using self-injection seeding,” Opt. Lett.35(17), 2885–2887 (2010). [CrossRef] [PubMed]

Cited By

Alert me when this paper is cited

OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.


« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited