VECSEL Semiconductor Lasers: A Path to High‐Power, Quality Beam and UV to IR Wavelength by Design

Abstract

Since its invention and demonstration in 1960, several types of laser have been developed, such as solid-state, semiconductor, gas, excimer, and dye lasers [1]. Today, lasers are used in a wide range of important applications, particularly in optical fiber communication, optical digital recording (CD, DVD, and Blu-ray), laser materials processing, biology and medicine, spectroscopy, imaging, entertainment, and many others. A number of properties enable the application of lasers in these diverse areas, each application requiring a particular combination of these properties. Some of the most important laser properties are laser emission wavelength; output optical power; method of laser excitation, whether by optical pumping or electrical current injection; laser power consumption and efficiency; high-speed modulation or short pulse generation ability; wavelength tunability; output beam quality; device size; and so on. Thus, optical fiber communication [2], a major application that enables modern Internet, commonly requires lasers with emission wavelengths in the 1.55 mm lowloss band of glass fibers and with single-transverse mode output beams for coupling into single-mode optical fibers. Typically, a given laser type excels in some of these properties, while exhibiting shortcomings in others. For example, by using different material compositions and structures, the most widely used semiconductor diode laser [3][4][5][6][7][8][9][10][11][12] can cover a wide range of wavelengths from the ultraviolet (UV) to the mid-IR, can be advantageously driven by diode current injection, and is very compact and efficient. However, the good beam quality, that is, single-transverse mode nearcircular beam operation, can be typically achieved in semiconductor lasers only for output powers below 1 W. Much higher power levels are achievable from semiconductor lasers only with large aspect ratio highly multimoded poor quality optical beams. On the other hand, the solid-state lasers [13,14], including fiber lasers [15], can emit hundreds of watts of output power with excellent beam quality, however, their emission wavelengths are restricted to discrete values of electronic transitions in ions, such as the classic 1064 nm wavelength of the Nd:YAG laser, making them Semiconductor Disk Lasers. Physics and Technology. Edited by Oleg G. Okhotnikov

Thermal management of GaInNAs/GaAs VECSELs

“…EELs may emit very intense high−power radiation of the order of many watts, but their output beams contain many longitudi− nal modes and are very divergent, with astigmatism effects [1]. On the other hand, VCSELs emit low−divergent circu− larly symmetric output beams without astigmatism, but their single−mode emission is limited to relatively low output power of the order of a few milliwatts [2].…”

Treatment of telangiectasia on the cheeks with a compact yellow (585 nm) semiconductor laser and a green (532 nm) KTP laser: a randomized double‐blinded split‐face trial

“…To address the needs of the dermatologic community a novel laser technology, namely optically pumped semiconductor disk laser (SDL), has emerged to provide a compact and cost‐effective alternative for a yellow laser source. SDLs, also known as VECSELs (vertical external‐cavity surface‐emitting lasers), are recognized for their power scaling abilities, transverse mode control and the ability to tailor the emission wavelength according to specific application needs . With the addition of wavelength selective components and suitable laser cavity configurations, SDLs can also be designed to emit narrow linewidth and have a wavelength tuning range up to tens of nanometers .…”

Continuous-wave VECSEL Raman laser with tunable lime-yellow-orange output

“…Optically-pumped semiconductor vertical-external-cavity surface-emitting lasers (VECSELs) have evolved rapidly during the past decade [1]. They are a very versatile type of laser, because a wide range of semiconductor materials can deliver a selection of emission wavelengths and tunability, and because the open cavity design enables easy integration of intracavity components and nonlinear processes.…”