A laser structure comprising a first photonic crystal surface emitting laser (PCSEL), a second PCSEL, and a coupling region that extends between the first PCSEL and the second PCSEL along a longitudinal axis and that is electrically controllable so as to be capable of coherently coupling the first PCSEL to the second PCSEL. Each PCSEL include an active layer, a photonic crystal, and a two-dimensional periodic array distributed in an array plane parallel to the longitudinal axis within the photonic crystal where the two-dimensional periodic array is formed of regions having a refractive index that is different to the surrounding photonic crystal.

A tunable wavelength laser comprising a laser cavity formed by a broadband mirror and a comb mirror. The laser cavity comprising a gain region. The laser cavity is configured such that a non-integer number of cavity modes of the laser cavity are between two consecutive reflection peaks of the comb mirror.

A VCSEL can include: an electro-optic modulator between a lasing active region and a light emitting surface. The electro-optic modulator can include: an electro-optically active region; a modulator mirror region over the electro-optically active region; and at least one electrical insulator region separating the modulator mirror region into at least two separate modulator mirror cavities electrically isolated from each other, wherein each separate modulator mirror cavity and a longitudinally aligned portion of the electro-optically active region form an electro-optic modulator cavity. A method of emitting light from a VCSEL can include: emitting a laser beam from the lasing active region along a longitudinal axis; and changing a refractive index of one electro-optic modulator cavity so as to steer the laser beam from the longitudinal axis.

An optical modulator includes a light-emitting device and an upper electrode disposed on the light-emitting device. The upper electrode includes at least one first electrode portion for injecting a direct current to form a direct-current modulated segment, and a second electrode portion for injecting an alternating current to form an alternating-current modulated segment. The at least one first electrode portion and the second electrode portion are spaced apart from each other, and have a first length and a second length, respectively. The first length is greater than the second length. A method for manufacturing the optical modulator is also provided herein.

A laser comprising a laser cavity formed by a first optical reflector, a gain region, a second optical reflector having a plurality of reflection peaks, and at least one optically active region. The first mirror may be a DBR or comb mirror and the second mirror may be a comb mirror. The spectral reflectance of the second optical reflector is adjusted at least partially based on an electric signal received form the optically active region such that only one reflection peak is aligned with a cavity mode formed by the first and second reflector.

A tunable vertical-cavity surface-emitting laser (VCSEL) is provided. The VCSEL includes a VCSEL emission structure, piezoelectric material, and a piezoelectric electrode. The VCSEL emission structure includes a first reflector; a second reflector; and an active cavity material structure disposed between the first and second reflectors. The active cavity material structure includes an active region. The piezoelectric material is mechanically coupled to the VCSEL emission structure such that when the piezoelectric material experiences a mechanical stress, the mechanical stress is transferred to the active cavity material structure of the VCSEL emission structure. The piezoelectric electrode is designed to cause an electric field within the piezoelectric material. The electric field causes the piezoelectric material to experience the mechanical stress, which causes the active cavity material structure to experience the mechanical stress, which causes the emission wavelength of the VCSEL to be modified from a nominal wavelength of the VCSEL.

A QCL may include a substrate, an emitting facet, and semiconductor layers adjacent the substrate and defining an active region. The active region may have a longitudinal axis canted at an oblique angle to the emitting facet of the substrate. The QCL may include an optical grating being adjacent the active region and configured to emit one of a CW laser output or a pulsed laser output through the emitting facet of substrate.

A transistor for emitting laser with a fixed frequency includes a first region, a second region, at least one quantum well, and a third region. The at least one quantum well is installed in the second region, and the second region is coupled between the first region and the third region. When one of the first region, the second region, and the third region receives two signals, or two of the first region, the second region, and the third region receive the two signals respectively, the at least one quantum well emits the laser with the fixed frequency.

A monolithic QCL/APD IR Transceiver in which the QCL transmitter and APD receiver have the same N MQW stage composition and variation in thickness in the z direction for all positions in x and y directions. The heterostructure is configured via asymmetric stages, additional stages for the APD or by reversing the polarity of the p-n junction for the APD or a combination thereof such that the upper energy state in the QCL under forward bias is confined to the quantum well and in the APD under reverse bias is near the top of the quantum well in energy and localized in the quantum well to spatially overlap with the lower energy state to facilitate detection of echo photons. The QCL and APD may be positioned end-to-end, side-by-side or as a common region of the heterostructure.

A transistor for emitting laser with a fixed frequency includes a first region, a second region, at least one quantum well, and a third region. The at least one quantum well is installed in the second region, and the second region is coupled between the first region and the third region. When one of the first region, the second region, and the third region receives two signals, or two of the first region, the second region, and the third region receive the two signals respectively, the at least one quantum well emits the laser with the fixed frequency.