Compact Flattop Laser Beam Shaper Using Vectorial Vortex

• Wen Cheng, Wei Han, and Qiwen Zhan
• received 03/18/2013; accepted 05/14/2013; posted 05/15/2013; Doc. ID 187243
• [full text: PDF (845) KB)]
• Abstract: In this paper, we demonstrate a compact flattop beam shaper to realize two-dimensional flattop focus through generating second order Full Poincaré beam. Liquid crystal material is used in the device as the voltage-dependent birefringent material to provide appropriate phase retardation modulation. The beam shaper is fabricated and tested. Experimental results show that high quality flattop profiles can be obtained with steep edge roll-off. The tolerance of different input beam sizes of the beam shaper is also verified in the experimental demonstration.

Keywords (OCIS):

• (050.1960) Diffraction and gratings : Diffraction theory
• (140.3300) Lasers and laser optics : Laser beam shaping
• (160.3710) Materials : Liquid crystals
• (230.6120) Optical devices : Spatial light modulators
• (260.5430) Physical optics : Polarization

Active and passive SWIR and NIR imaging for horizontal and slant paths close to ground

• Ove Steinvall, Magnus Elmqvist, Tomas Chevalier, and Ove Gustafsson
• received 02/04/2013; accepted 05/14/2013; posted 05/16/2013; Doc. ID 184765
• [full text: PDF (4334) KB)]
• Abstract: This paper investigates active and passive SWIR imaging for slant paths close to ground. The main sensor, a gated SWIR camera was collecting both passive and active images along a 2 km long path over an airfield and also from our roof top laboratory looking over open fields. For some investigations we also used a gated system working in the NIR region and thermal as well as color CCD cameras. The sensor was elevated by a lift in steps from 1.6-13.5 meters or placed in a roof top laboratory 13 m above ground.Targets were resolution charts and human targets. The turbulence was measured along the path with anemometers and scintillometers. The image performance was evaluated by measurement of the image blur and also by performing observer perception tests. The results reveal a strong dependence on the sensor height especially during daytime

Keywords (OCIS):

• (280.3420) Remote sensing and sensors : Laser sensors
• (110.0115) Imaging systems : Imaging through turbulent media

12345678910111213141516171819202122232425262728293031Interference-based multiple-image encryption with silhouette removal by position multiplexing

• Yi Qin and Qiong Gong
• received 04/02/2013; accepted 05/13/2013; posted 05/13/2013; Doc. ID 188134
• [full text: PDF (3974) KB)]
• Abstract: 12345678910111213141516171819202122232425262728293031An approach to multiple-image optical encryption based on encryption and verification method based on interference and position multiplexing is proposed. In the encryption process, multiple images are analytically hidden into three phase only masks (POMs). The encryption algorithm for this new method is quite simple and does not need iterative encoding. For decryption, both the digital method and optical method could be employed. Also, we analyze the multiplexing capacity through the correlation coefficient. In addition, the silhouette problem that exists in previous interference-based encryption method with two POMs can be eliminated during the generation procedure of POMs based on the interference principle. Simulation results are presented to verify the validity of the proposed approach.

Keywords (OCIS):

• (070.0070) Fourier optics and signal processing : Fourier optics and signal processing
• (100.1160) Image processing : Analog optical image processing

Controlling the transverse localization of THz waves in an InSb based disordered waveguide array using temperature

• Abbas Ghasempour Ardakani
• received 02/19/2013; accepted 05/12/2013; posted 05/15/2013; Doc. ID 185499
• [full text: PDF (613) KB)]
• Abstract: We propose that the transverse localization in semiconductor based disordered waveguide array can be made controllable in the terahertz regime by changing the ambient temperature. The standard scalar Helmholtz equation is used to describe terahertz wave propagation through the waveguide array. It is first assumed that the waveguides are fabricated from InSb semiconductor, while the spacing between them is composed of a dielectric. The disorder is introduced in the system by random refractive index of the spacing medium. Our results demonstrate that the transverse width of the output intensity increases with increasing the temperature. This effect is attributed to the temperature-dependent electric permittivity of the used semiconductor. Then, the waveguides are composed of a dielectric and the spacing between them filled with InSb semiconductor. For this case, to introduce disorder, we assumed that the refractive index of the waveguides is randomized. It is found that the output intensity becomes more localized with increasing temperature. However, further increasing the temperature leads to the delocalization of output intensity. The effect of spacing between adjacent waveguides on the threshold degree of disorder has also investigated.

Keywords (OCIS):

• (260.3160) Physical optics : Interference
• (070.7345) Fourier optics and signal processing : Wave propagation

Study of reference waves in single-exposure generalized phase-shifting digital holography

• Masatoshi Imbe and Takanori Nomura
• received 03/05/2013; accepted 05/11/2013; posted 05/15/2013; Doc. ID 186446
• [full text: PDF (3394) KB)]
• Abstract: The appropriate reference wave in single-exposure phase-shifting digital holography using a random-complex-amplitude encoded reference wave is experimentally investigated.Although the reference wave is generalized, the quality of reconstructed images depends on it.Furthermore, when the reference wave satisfies a certain condition, reconstructed images can not be obtained in this method.After the certain condition is presented, the appropriate condition is studied using a speckle property.Experimental results are given to investigate relations between the quality of reconstructed images and the sizes of speckles of the reference waves.The results proves that the appropriate reference wave exists in this method.

Keywords (OCIS):

• (030.6140) Coherence and statistical optics : Speckle
• (050.5080) Diffraction and gratings : Phase shift
• (090.1995) Holography : Digital holography
• (110.7348) Imaging systems : Wavefront encoding

Design and Development of a injection-molded demultiplexer for optical communication systems in the visible range

• S. Höll, M. Haupt, and U. Fischer
• received 03/06/2013; accepted 05/11/2013; posted 05/14/2013; Doc. ID 186107
• [full text: PDF (1649) KB)]
• Abstract: Optical simulation software based on the ray tracing method offers easy and fast results in imaging optics. This method can also be applied in other fields of light propagation. For short distance communications polymer optical fibers (POFs) are gradually gaining importance. This kind of fiber offers a larger core diameter, e.g. step index POF features a core diameter of 980 µm. Consequently, POFs have a large number of modes (>3 million modes) in the visible range and ray tracing could be used to simulate the propagation of light. This simulation method is not only applicable for the fiber itself but also for the key components of a complete POF network, e.g. couplers or other key-elements of the transmission line. In this paper a demultiplexer designed and developed by means of ray tracing is presented. Compared to the classical optical design, requirements for optimal design differ particularly with regard to minimize the insertion loss. The basis of the presented key element is a wavelength division multiplex device using a Rowland spectrometer set-up. In this approach the input fiber carries multiple wavelengths, which will be divided into multiple output fibers that transmit only one wavelength. To adapt the basic set-up to POF, the guidance of light in this element has to be changed fundamentally. Here, a monolithic approach is presented with a blazed grating using an aspheric mirror to minimize most of the aberrations. In the simulations the POF is represented by an area light source, while the grating is analyzed for different orders and the highest possible efficiency. In general, the element should be designed in a way that it can be produced with a mass production technology like injection molding in order to offer a reasonable price less than 10 EUR. However, designing the elements with regard to injection molding leads to some inherent challenges. The microstructure of an optical grating and the thick-walled 3D molded parts both result in high demands on the injection molding process. This also requires a complex machining of the molding tool. Therefore, different experiments are done to optimize the process parameter, find the best molding material, and find a suitable machining method for the molding tool. The paper will describe the development of the demultiplexer by means of ray tracing simulations step by step. Also the process steps and the realized solutions for the injection molding are described.

Keywords (OCIS):

• (060.2330) Fiber optics and optical communications : Fiber optics communications
• (060.4230) Fiber optics and optical communications : Multiplexing
• (060.4510) Fiber optics and optical communications : Optical communications
• (220.4830) Optical design and fabrication : Systems design
• (230.1950) Optical devices : Diffraction gratings

12345678910111213141516171819202122232425262728293031Uniform Illumination Design by Configuration of LEDs and Optimization of LED Lens for Large-scale Color Mixing Applications

• Peng Liu, Huihui Wang, Rengmao Wu, Yang Yang, Yaqin Zhang, Zhenrong Zheng, Haifeng Li, and Xu Liu
• received 03/20/2013; accepted 05/11/2013; posted 05/13/2013; Doc. ID 187470
• [full text: PDF (1457) KB)]
• Abstract: 12345678910111213141516171819202122232425262728293031In many applications, the emitting light from LEDs with different colors need to be mixed together on a large scale plane and this illumination mode is usually generated with a diffuser. Abandoning the traditional method, we proposed a LED color mixing method which can produce both high color uniformity and irradiance uniformity pattern. This method is composed of two main aspects: arrangement of irradiance array and design of LED lens. With the method, an independent rectangular irradiance distribution is generated by each lens unit, and the large scale color uniform illumination is obtained by arraying the irradiance distribution. A 3×3 array of LED module units consisting of 36 LED lens units with 4 different colors are designed, and a desired result with high color uniformity is obtained.

Keywords (OCIS):

• (220.3630) Optical design and fabrication : Lenses
• (230.3670) Optical devices : Light-emitting diodes
• (220.2945) Optical design and fabrication : Illumination design
• (220.4298) Optical design and fabrication : Nonimaging optics

12345678910111213141516171819202122232425262728293031Improved Algorithm for Multiwavelength Single-Shot Interferometric Surface Profiling: Speeding Up the Multiwavelength-Integrated Local Model Fitting Method by Local Information Sharing

• Keisuke Nakata, Masashi Sugiyama, Katsuichi Kitagawa, and Masafumi Otsuki
• received 02/12/2013; accepted 05/11/2013; posted 05/13/2013; Doc. ID 185134
• [full text: PDF (6155) KB)]
• Abstract: 12345678910111213141516171819202122232425262728293031The local model fitting (LMF) methodis a single-shot interferometric surface profiling algorithmthat possesses non-destructive, fast, accurate, and robust measurement capabilities.To extend the measurement range of LMF,extensions based on multiwavelength light sources such asthe multiwavelength-matched LMF (MM-LMF) method andthe multiwavelength-integrated LMF (MI-LMF) method were proposed recently.MM-LMF is computationally efficient but it tends to suffer from phase unwrapping errors,whereas MI-LMF tends to be accurate but it is computationally expensive.In this paper, we improve the computational efficiency of MI-LMFby combining it with MM-LMF via local information sharing.Through actual experiments, we demonstrate that the proposed methodis approximately 10 times faster than the original MI-LMF method,with measurement accuracy kept comparable.

Keywords (OCIS):

• (240.0240) Optics at surfaces : Optics at surfaces
• (240.6700) Optics at surfaces : Surfaces

Sensitivity improvement of Micro-grating accelerometer based on differential detection method

• Xiao Wang, Lishuang Feng, Baoyin Yao, and Xiaoyuan Ren
• received 04/03/2013; accepted 05/11/2013; posted 05/16/2013; Doc. ID 188209
• [full text: PDF (2538) KB)]
• Abstract: A differential detection method (DTM) with utility-type and ease of realization for micro-grating accelerometer is reported so as to reduce the common-mode noise and improve the sensitivity of micro-grating accelerometer. The theoretical model is established based on scalar diffraction theory for differential detection. According to the simulation and analysis of the DTM, the theoretical result shows that the sensitivity of the micro-grating accelerometer can be improved at least twice. Based on the analysis, the detection circuit is designed with proper parameters and devices for the hand-held experimental prototype, which is realized with our micro-grating acceleration sensor (MGAS) fabricated by inductively coupled plasma (ICP), lift-off, and anodic bonding of glass/silicon, etc. The experiment of the prototype is conducted with the turntable. Compared with the single-order detection method whose sensitivities are 6.797V/g (0th order, 1g = 9.8 m/s²) and 7.767V/g (1st order), the result of differential detection method shows that the sensitivity of the micro-grating accelerometer is 18.61V/g with an improvement for over two times. And the overall signal-to-noise ratio (SNR) improvement is 6.47dB with the input of 0.86g.

Keywords (OCIS):

• (120.1880) Instrumentation, measurement, and metrology : Detection
• (120.3180) Instrumentation, measurement, and metrology : Interferometry
• (230.1950) Optical devices : Diffraction gratings
• (280.4788) Remote sensing and sensors : Optical sensing and sensors

Fast Calculation Method of Complex Space Target's Optical Cross Section

• Yi Han, Huayan Sun, Yingchun Li, and Huichao Guo
• received 03/11/2013; accepted 05/10/2013; posted 05/15/2013; Doc. ID 186591
• [full text: PDF (865) KB)]
• Abstract: This paper utilizes the Optical Cross Section (OCS) to characterize the optical scattering characteristics of space target under the conditions of sun lighting. First, we derive the mathematical expression of OCS according to the theory of radiometric, and deduce the analytical OCS expressions of the Lambert cylinder and sphere. Then we put forward the fast calculation method of complex space target’s OCS based on the visual computing method by utilizing OpenGL and target 3ds model. Through the OCS simulation of Lambert bodies, we verify the accuracy and computational speed of the algorithm, and the results show that the absolute error is less than 0.01m2, and the spending time is less than 0.05s. At last we select the material BRDF model parameters in the visible bands for three actual complex target models and calculate their respective OCS curves.

Keywords (OCIS):

• (290.1350) Scattering : Backscattering
• (350.5610) Other areas of optics : Radiation
• (290.1483) Scattering : BSDF, BRDF, and BTDF

12345678910111213141516171819202122232425262728293031High spatial resolution zonal wavefront reconstruction with improved initial value determination scheme for lateral shearing interferometry

• Fengzhao Dai, Feng Tang, Xiangzhao Wang, Osami Sasaki, and Min Zhang
• received 01/11/2013; accepted 05/09/2013; posted 05/10/2013; Doc. ID 183336
• [full text: PDF (3327) KB)]
• Abstract: 12345678910111213141516171819202122232425262728293031An improved high spatial resolution zonal method is proposed for wavefront reconstruction in lateral shearing interferometry. The main advance of the proposed method is that the initial values are determined by modal reconstruction, the determined initial values are more accurate than that determined by linear interpolation as that used in previous high spatial resolution zonal method. The validity of the proposed method is investigated through comparison with the previous high spatial resolution zonal method by some numerical experiments. The simulation results show that the reconstruction of the proposed method is more accurate and more stable to the shear ratios. Furthermore, a comprehensive property comparison is performed among the proposed method, the previous high spatial resolution zonal method, and the modal method.

Keywords (OCIS):

• (120.3940) Instrumentation, measurement, and metrology : Metrology
• (120.5050) Instrumentation, measurement, and metrology : Phase measurement

12345678910111213141516171819202122232425262728293031Sensitive Detection of CO2 Implementing Tuneable Thulium-doped ‘All-fibre’ Laser

• K Bremer, A Pal, S Yao, E Lewis, R Sen, T Sun, and K T V Grattan
• received 01/16/2013; accepted 05/09/2013; posted 05/10/2013; Doc. ID 183659
• [full text: PDF (926) KB)]
• Abstract: 12345678910111213141516171819202122232425262728293031In this paper a compact, yet sensitive gas detection system based on a modulated, tuneable Thulium-doped fibre laser in the 2 µm wavelength region is reported. The laser operating wavelength range centred at a wavelength of 1.995 µm has been selected to access the R(50) transition ( ) of CO2 based on its line-strength and achieving isolation from interfering high-temperature water absorption features. The laser line-width and tuning range are optimized accordingly. The modulation of the fibre laser, through pump source modulation, and ‘locking’ detection mechanism has been utilized to eliminate laser intensity noise and therefore to obtain a compact gas sensor with high sensitivity. The absorption spectrum, as well as the line-strength and the concentration level of CO2, have been monitored through absorption spectroscopy techniques. The measured minimum detectable concentration of CO2 obtained using the system shows that it is quite capable of detecting trace gas in the ppm level. The stable laser performance achieved in the sensor system illustrates its potential for the development of practical, compact yet sensitive fibre laser based gas sensor systems.

Keywords (OCIS):

• (060.4080) Fiber optics and optical communications : Modulation
• (140.3600) Lasers and laser optics : Lasers, tunable
• (010.1030) Atmospheric and oceanic optics : Absorption
• (060.3510) Fiber optics and optical communications : Lasers, fiber

12345678910111213141516171819202122232425262728293031Plasma-Debris Sputter Resistant X-ray Mirror

• Sho Amano, Tomoaki Inoue, and Tetsuo Harada
• received 02/11/2013; accepted 05/08/2013; posted 05/09/2013; Doc. ID 185142
• [full text: PDF (3235) KB)]
• Abstract: 12345678910111213141516171819202122232425262728293031A diamond-like carbon (DLC) mirror, used as a grazing incident mirror in a plasma X-ray source, exhibits a high resistance to plasma debris sputtering. Good mirror reflectivity at a wavelength of 13.5 nm was confirmed using synchrotron radiation at the NewSUBARU facility. The erosion rate due to plasma debris sputtered at the incident debris angle of 20° was measured using a laser-produced Xe plasma source developed by the authors. The results indicate that the DLC film has a 5- and 15-fold higher sputtering resistance compared to films made of the traditional mirror materials Ru and Au, respectively. Because the DLC mirror retains a high sputtering resistance to Sn ions, it may be effective in Sn plasma source applications. We conclude that a grazing incident X-ray mirror coated with DLC can be of use as a plasma debris sputtering resistant mirror.

Keywords (OCIS):

• (340.7470) X-ray optics : X-ray mirrors
• (340.7480) X-ray optics : X-rays, soft x-rays, extreme ultraviolet (EUV)
• (350.1820) Other areas of optics : Damage
• (350.5400) Other areas of optics : Plasmas

12345678910111213141516171819202122232425262728293031Effects of surface roughness on optical properties andsensitivity of fiber-optic evanescent wave sensors

• Nianbing Zhong, Xun Zhu, Qiang Liao, Yongzhong Wang, Rong Chen, and Yahui Sun
• received 03/01/2013; accepted 05/08/2013; posted 05/09/2013; Doc. ID 186153
• [full text: PDF (2339) KB)]
• Abstract: 12345678910111213141516171819202122232425262728293031The effects of surface roughness on the light transmission properties and sensitivity of fiber-optic evanescent wave sensors are investigated. A simple method of increasing the sensitivity based on the surface roughness (pit depth δ and diameter ∆) and incident angle Ui of light rays on the fiber input end is proposed. We discovered that as 2δ/∆ increases, the transmitted light intensity decreases, but the sensitivity initially increases and then decreases. In sensors containing fibers of various roughnesses, the sensitivity to glucose solutions reached -11.7 mW/riu at 2δ/∆ = 0.32 and increased further to -15.3 mW/riu with proper adjustment of Ui.

Keywords (OCIS):

• (060.0060) Fiber optics and optical communications : Fiber optics and optical communications
• (080.0080) Geometric optics : Geometric optics
• (220.0220) Optical design and fabrication : Optical design and fabrication
• (240.0240) Optics at surfaces : Optics at surfaces
• (280.4788) Remote sensing and sensors : Optical sensing and sensors

12345678910111213141516171819202122232425262728293031Nonlinear approaches for the single-distance phase retrievalproblem involving regularizations with sparsity constraints

• Valentina Davidoiu, Bruno Sixou, Max Langer, and Francoise Peyrin
• received 01/31/2013; accepted 05/07/2013; posted 05/07/2013; Doc. ID 184565
• [full text: PDF (2017) KB)]
• Abstract: 12345678910111213141516171819202122232425262728293031The phase retrieval process is a nonlinear ill-posed problem. The Fresnel diraction patterns obtained with hard X-rays synchrotrons beams can be used to retrieve the phase contrast. In this work, we present a convergence comparison of several nonlinear approaches for the phase retrieval probleminvolving regularizations with sparsity constraints. The phase solution is assumed to have a sparse representation with respect to an orthonormal wavelets basis.One approach uses alternatively a solution of the nonlinear problem based on the Frechet derivative and a solution of the linear problem in wavelet coordinate with an iterative thresholding. A second method is the one proposed by Teschke et al. which generalizes to a nonlinear problem the classical thresholding algorithm. The best simulation results are obtained by the fifirst method for the various noise levels and initializations investigated.The algorithms were tested on a 3D Shepp-Logan phantom corrupted by white Gaussian noise. The best results are obtained by the first method. The low frequency noise is also significantly decreased.

Keywords (OCIS):

• (100.3190) Image processing : Inverse problems
• (100.5070) Image processing : Phase retrieval
• (110.7440) Imaging systems : X-ray imaging
• (180.7460) Microscopy : X-ray microscopy
• (110.7410) Imaging systems : Wavelets

12345678910111213141516171819202122232425262728293031(HM) Liquid Crystal-Carbon Nanotube Composites with Photo-settable Reversible and Memory Electro-optic Modes

• Oleg Yaroshchuk, Sergiy Tomylko, Igor Gvozdovskyy, and Rumiko Yamaguchi
• received 02/20/2013; accepted 05/07/2013; posted 05/07/2013; Doc. ID 185689
• [full text: PDF (925) KB)]
• Abstract: 12345678910111213141516171819202122232425262728293031The photoresponsive electro-optical composites based on the liquid crystal (LC) with the optically controlled chirality and a minute amount of carbon nanotubes (CNTs) are studied. In the LC cells with homeotropic anchoring these composites exhibit a dual-mode operation with the optical switching between reversible and memory mode. It is found that the memory response is associated with the oily streak network that stabilizes the LC orientation reached in an electric field. In turn, the reversible mode is caused by the unwound cholesteric state. Potential applications of these composites are discussed.

Keywords (OCIS):

• (160.2100) Materials : Electro-optical materials
• (230.3720) Optical devices : Liquid-crystal devices

12345678910111213141516171819202122232425262728293031Bicell-photodetector in the Fourier plane as a fiberoptic homodyne phase demodulator - theoreticalmodel and experimental results

• Idzi MERTA, Zbyszek HOLDYNSKI, and Leszek JAROSZEWICZ
• received 04/03/2013; accepted 05/07/2013; posted 05/08/2013; Doc. ID 188196
• [full text: PDF (767) KB)]
• Abstract: 12345678910111213141516171819202122232425262728293031A concept of the Young interference experiment has been applied in the design of a fiber optic homodyne phase demodulator. The system is a based on bicell-photodetector in the Fourier plane. The above system has been designed, described and verified together with an estimation of the minimization of phase measurement error in connection with the distance between photodetectors, wavelength and focal length of the Fourier lens. The fundamental investigation concerning the choice of a distance between photodetectors and its influence on the demodulator’s linearity has been presented and discussed, as well.

Keywords (OCIS):

• (040.5160) Detectors : Photodetectors
• (070.0070) Fourier optics and signal processing : Fourier optics and signal processing
• (120.2650) Instrumentation, measurement, and metrology : Fringe analysis
• (110.5086) Imaging systems : Phase unwrapping

12345678910111213141516171819202122232425262728293031Ultra high contrast from a frequency doubled CPA beamline

• David Hillier, Colin Danson, Stuart Duffield, David Egan, Stephen Elsmere, Mark Girling, Ewan Harvey, Nicholas Hopps, Michael Normal, Stefan Parker, Paul Treadwell, David Winter, and Thomas Bett
• received 03/06/2013; accepted 05/07/2013; posted 05/13/2013; Doc. ID 186469
• [full text: PDF (2473) KB)]
• Abstract: 12345678910111213141516171819202122232425262728293031This paper describes frequency doubled operation of a high energy chirped pulse amplification beamline. Efficient type-I second harmonic generation was achieved using a 3 mm thick 320 mm aperture KDP crystal. Shots were fired at a range of energies achieving over 100 J in a sub-picosecond, 527 nm laser pulse with a power contrast of 1014.

Keywords (OCIS):

• (140.3530) Lasers and laser optics : Lasers, neodymium
• (190.2620) Nonlinear optics : Harmonic generation and mixing
• (320.7090) Ultrafast optics : Ultrafast lasers
• (320.7110) Ultrafast optics : Ultrafast nonlinear optics
• (140.3515) Lasers and laser optics : Lasers, frequency doubled

Determination of piezooptic coefficients of crystals by means of four-point bending

• Oleh Krupych, Viktoriya Savaryn, Andriy Krupych, Ivan Klymiv, and Rostyslav Vlokh
• received 03/18/2013; accepted 05/07/2013; posted 05/16/2013; Doc. ID 187369
• [full text: PDF (1681) KB)]
• Abstract: A technique developed recently for determining piezooptic coefficients of isotropic opti-cal media, which represents a combination of digital imaging laser interferometry and a classical four-point bending method, is generalized and applied to a single-crystalline anisotropic material. The peculiarities of measuring procedures and data processing for the case of optically uniaxial crystals are described in details. The capabilities of the tech-nique are tested on the example of canonical nonlinear optical crystal LiNbO3. High precision achieved in determination of the piezooptic coefficients for isotropic and anisot-ropic materials testifies that the technique should be both versatile and reliable.

Keywords (OCIS):

• (160.3730) Materials : Lithium niobate
• (260.0260) Physical optics : Physical optics
• (260.1180) Physical optics : Crystal optics
• (260.1440) Physical optics : Birefringence
• (260.3160) Physical optics : Interference
• (260.2710) Physical optics : Inhomogeneous optical media

Lens Design with Reduced Sensitivity to Thermally Induced Stress Birefringence

• Andrew Kurtz and Joseph Bietry
• received 04/09/2013; accepted 05/06/2013; posted 05/16/2013; Doc. ID 188530
• [full text: PDF (583) KB)]
• Abstract: In optical systems required to maintain the polarization states of the transiting light, mechanically induced stress birefringence can degrade performance, at least locally altering polarization phase and ultimately reducing polarization contrast. Although thermally induced stress birefringence can cause similar problems in imaging systems bearing high optical flux, appropriate design approaches to resolve this problem have been lacking. This paper first develops criteria to select optical glasses with reduced sensitivity to thermally induced stress birefringence. The design of projection lenses using the resulting thermal stress desensitized reduced glass list is then discussed, as is the application of such lenses in laser projection systems.

Keywords (OCIS):

• (160.2750) Materials : Glass and other amorphous materials
• (220.3620) Optical design and fabrication : Lens system design
• (220.4830) Optical design and fabrication : Systems design
• (260.1440) Physical optics : Birefringence
• (260.5430) Physical optics : Polarization