Introduction for the joint special issue on Spatial and Polarization Dynamics of Semiconductor Lasers
Several recent developments have resulted in considerable progress in the study of transverse effects and spatial mode dynamics in semiconductor lasers. Demands on higher and higher output powers have led to the development of wide-stripe lasers, coupled laser arrays, integrated master-oscillator power amplifiers (MOPAs), and other more complex laser structures for which spatial dependence of the laser mode becomes important. This is especially true for the vertical-cavity surface-emitting lasers (VCSELs), devices that have recently become commercially available and are being proposed for a multitude of interesting applications. In the case of a VCSEL, the transverse-mode behavior is inherently more complex compared with the traditional edge-emitting lasers because of a large Fresnel number associated with VCSELs. The recent interest in spatio-temporal dynamics of such lasers as an example of well-controlled, spatially extended, self-organizing systems has led to new understanding about patterns, defects, and other coherent and incoherent structures, all being important to large-aperture diode lasers.
While most studies were restricted to simple few-level models at the time when the first special issue of Journal of Optical Society of America (JOSA B) on this topic was published in 1990, more and more researchers are beginning to use models that describe semiconductor lasers more accurately. Furthermore, transverse-mode structures are generally coupled with the polarization of the laser field in the cavity. The issue of polarization has become especially relevant for VCSELs because of their unique geometry.
Considerable attention has been paid over the last few years to understand the polarization dynamics of VCSELs. Finally, it has become possible recently to measure near-field profiles with a resolution ~10 nm using a scanning near-field microscope. This newly acquired tool is likely to become important for beam diagnostics and for comparing numerically simulated results with the experimental data. It is these converging trends and exiting new developments that has led to this joint special issue of Optics Express and JOSA B on “Spatial and Polarization Dynamics of Semiconductor Lasers.”
The special issue serves to give a snapshot of the recent progress in the study of spatial and polarization dynamics in semiconductor lasers. Altogether 20 papers were accepted for publication in the joint issue. Four of them, with video animations, are being published in this issue of Optics Express, under the guidance of Joseph Haus. The remaining sixteen papers, a list of which is provided below, will be published in the traditional format in the November issue of JOSA B.
To help the reader, the JOSA B papers are subdivided into the following five categories:
(1) Transverse mode dynamics in Edge-emitting lasers;
(2) Transverse-Mode Dynamics in VCSELs;
(3) Microcavity Solitons;
(4) Polarization Dynamics in VCSELs;
(5) Laser Noise.
Consistent with the theme of the special issue, all papers deal with either spatial dynamics or/and the polarization effects occurring in semiconductor lasers. Furthermore, as a natural reflection of the prevailing dominance of VCSELs, fifteen papers out of 20 deal with VCSELs.
Given the high quality of the papers that appear in this issue in spite of the time constraints we had, we believe that the special issue not only is timely but should also prove useful to the researchers working in the field of semiconductor lasers. We thank all the contributors for their effort to meet the tight deadlines. We would like to thank the staff at the JOSA B manuscript office, especially Alexine Moore, for the very efficient professional help and assistance. Thanks also to Valerie Kambis in the editorial office and to Jennifer Martin, Optics Express staff.
Govind P. Agrawal
Institute of Optics
University of Rochester
Rochester, New York 14627
Computational Quantum Optoelectronics
NASA Ames Research Center, M/S T27A-1
Moffett Field, California 94035-1000
Phone: 650-604 3983
Fax: 650-604 3957
Maxi San Miguel
Instituto Mediterraneo de Estudios Avanzados
Campus Universitat Illes Balears
E-07071 Palma de Mallorca, Spain