A vertical cavity surface emitting laser (VCSEL) has a shortened overall laser cavity by combining the gain section with a distributed Bragg reflector (DBR). The overall cavity length can be contracted by placing gain structures inside the DBR. This generally applies to a number of semiconductor material systems and wavelength bands, but this scheme is very well suited to the AlGaAs/GaAs material system with strained InGaAs quantum wells as a gain medium, for example.

A surface emitting laser having a wide wavelength tunable band is provided.

A surface emitting laser includes a first reflecting mirror (102); a second reflecting mirror (116); and an active layer (104) arranged between the first reflecting mirror (102) and the second reflecting mirror (116), a gap being formed between the second reflecting mirror (116) and the active layer (104), an oscillation wavelength being tunable. The second reflecting mirror (116) includes a beam (108) comprising a single-crystal semiconductor, and a dielectric multilayer film (110) supported by the beam (108), and the dielectric multilayer film (110) is arranged in an opening (118) formed in the beam (108).

Disclosed herein are embodiments of a vertical external cavity surface emitting laser (VECSEL) device that utilizes an external micromirror array, and methods of fabricating and using the same. In one embodiment, a VECSEL device includes a gain chip, a mirror, and a micromirror array. The gain chip includes a gain medium. The micromirror array includes a plurality of curved micromirrors. The micromirror array and the mirror define an optical cavity, and the micromirror array is oriented such that at least one of the curved micromirrors is to reflect light generated by the gain medium back toward the gain medium along a length of the optical cavity.

A MEMS tunable VCSEL includes a membrane device having a mirror and a distal-side electrostatic cavity for displacing the mirror to increase a size of an optical cavity. A VCSEL device includes an active region for amplifying light. Then, a proximal-side electrostatic cavity is defined between the VCSEL device and the membrane device is used to displace the mirror to decrease a size of an optical cavity.

A very strong selection mechanism is provided in a tunable vertical cavity surface emitting laser (VCSEL) by manipulating the laser threshold to be different for TE and TM polarization by a employing a subwavelength grating in the laser cavity. The laser selects the polarization with the lowest threshold. The grating does not diffract and does not add loss to the cavity. It works by creating a large birefringence layer between the semiconductor and air sub-cavities of the full VCSEL. Multilayer stack calculations show that this results in a lower threshold for the TM polarization over the TE. This subwavelength grating layer, in one embodiment, replaces the AR coating on the semiconductor surface.

A high-speed, single-mode, high power, reliable and manufacturable wavelength-tunable light source operative to emit wavelength tunable radiation over a wavelength range contained in a wavelength span between about 950 nm and about 1150 nm, including a vertical cavity laser (VCL), the VCL having a gain region with at least one compressively strained quantum well containing Indium, Gallium, and Arsenic.

A wavelength-tunable vertical-cavity surface-emitting laser (VCSEL) with the use of microelectromechanical system (MEMS) technology is provided as a swept source for Optical Coherence Tomography (OCT). The wavelength-tunable VCSEL comprises a bottom mirror of the VCSEL, an active region, and a MEMS tunable upper mirror movable by electrostatic deflections. The bottom mirror comprising a GaAs based distributed Bragg reflector (DBR) stack, and the active region comprising multiple stacks of GaAs based quantum dot (QD) layers, are epitaxially grown on a GaAs substrate. The MEMS tunable upper mirror includes a membrane part supported by suspension beams, and an upper mirror comprising a dielectric DBR stack. The MEMS tunable quantum dots VCSEL can cover an operating wavelength range of more than 100 nm, preferably with a center wavelength between 250 and 1950 nm, and the sweeping rate can be from a few kHz to hundreds of kHz, and up to a few MHz.

A tunable source includes a short-cavity laser optimized for performance and reliability in SSOCT imaging systems, spectroscopic detection systems, and other types of detection and sensing systems. The short cavity laser has a large free spectral range cavity, fast tuning response and single transverse, longitudinal and polarization mode operation, and includes embodiments for fast and wide tuning, and optimized spectral shaping. Disclosed are both electrical and optical pumping in a MEMS-VCSEL geometry with mirror and gain regions optimized for wide tuning, high output power, and a variety of preferred wavelength ranges; and a semiconductor optical amplifier, combined with the short-cavity laser to produce high-power, spectrally shaped operation. Several preferred imaging and detection systems make use of this tunable source for optimized operation are also disclosed.

An optical device includes: a first reflector; a second reflector facing the reflector; a light emitter between the first reflector and the second reflector; a base supporting the second reflector with space between the light emitter and the second reflector; a piezoelectric body configured to, in response to application of drive voltage, deform to cause the second region to deform to drive the second reflector so as to change a distance between the first reflector and the second reflector. The base has a first region and a second region having a lower stiffness than the first region. The second region has the second reflector and the piezoelectric body thereon. The optical device is configured to emit a laser beam whose wavelength is changeable with the distance between the first reflector and the second reflector.

Discretely tunable laser systems include a continuously tunable laser for outputting a beam tunable among selectable frequencies, the selectable frequencies are separated in frequency by discrete frequency intervals, the discrete frequency intervals include a maximum interval and a minimum interval, where a difference between the maximum interval and the minimum interval is 100 MHz or less, and an external stabilization circuit coupled to the continuously tunable laser and a controller. The external stabilization circuit includes a first photodiode generating a first signal corresponding to a portion of the beam and an interferometer that produces resonances upon incidence of another portion of the beam. The resonances are equally spaced in frequency, with each defining one of the selectable frequencies. A second photodiode generates a second signal corresponding a transmission beam generated by the interferometer. The controller tunes the continuously tunable laser among the selectable frequencies based on the first and second signals.