Consistent with the present disclosure, a local oscillator is provided in a receiver. The local oscillator laser a first and second mirrors and phase section and heaters are provided adjacent each portion of the laser, such that the temperature and thus the frequency of light output from the local oscillator laser may be tuned. Applying electrical power, such as a current or voltage to the phase section may result in rapid frequency tuning of light output from the local oscillator laser but over a limited frequency range. Temperature changes to the mirror sections, however, may afford frequency tuning over a wider range, but frequency tuning the mirror sections requires more time than that required to tune the phase section. Consistent with the present disclosure, a tuning method and apparatus is provided that optimizes laser tuning by selectively tuning the phase and mirror sections.

An optoelectronic device including a semiconductor layer formed from a central segment and at least two lateral segments forming tensioning arms that extend along a longitudinal axis A1. The semiconductor layer furthermore includes at least two lateral segments forming electrical biasing arms that extend along a transverse axis A2 orthogonal to the axis A1.

A combination of microvalves and waveguides may enable the creation of reconfigurable on-chip light sources compatible with planar sample preparation and particle sensing architecture using either single-mode or multi-mode interference (MMI) waveguides. A first type of light source is a DFB laser source with lateral gratings created by the light valves. Moreover, feedback for creating a narrowband light source does not have to be a DFB grating in the active region. A DBR configuration (Bragg mirrors on one or both ends of the active region) or simple mirrors at the end of the cavity can also be used. Alternately, ring resonators may be created using a valve coupled to a bus waveguide where the active gain medium is either incorporated in the ring or inside an enclosed fluid. The active light source may be activated by moving a fluid trap and/or a solid-core optical component defining its active region.

A quantum dot comb laser, is provided that comprises a first waveguide having a first width; and a second waveguide running above the first waveguide that includes: a quantum dot layer; a first region of a second width less than the first width; a second region connected to the first region and comprising a reflective grating; and a third region connected at a first end to the second region and at a second end to an output surface wherein the third region tapers from the second width at the first end to a third width, less than the second width, at the second end.

A laser includes an active region surrounded by first and second waveguide layers. Two or more mask openings are formed within a dielectric layer on a surface parallel to the active region. A refractive grating is formed on the dielectric mask openings and includes three-dimensional grating features spaced apart in the light-propagation direction of the laser. The refractive grating provides modulation of a real part of the effective refractive index of the laser and modulation of the imaginary part is provided by modulation of the current flow through the mask openings.

A combination of microvalves and waveguides may enable the creation of reconfigurable on-chip light sources compatible with planar sample preparation and particle sensing architecture using either single-mode or multi-mode interference (MMI) waveguides. A first type of light source is a DFB laser source with lateral gratings created by the light valves. Moreover, feedback for creating a narrowband light source does not have to be a DFB grating in the active region. A DBR configuration (Bragg mirrors on one or both ends of the active region) or simple mirrors at the end of the cavity can also be used. Alternately, ring resonators may be created using a valve coupled to a bus waveguide where the active gain medium is either incorporated in the ring or inside an enclosed fluid. The active light source may be activated by moving a fluid trap and/or a solid-core optical component defining its active region.

A novel narrow linewidth laser device is disclosed that is formed monolithically on a semiconductor substrate, such as an indium phosphide substrate, that includes a continuous waveguide with a gain section and a grating section wherein a grating is constructed so that its power reflectivity profile has a ratio of reflectivity slope over reflectivity at the 3 dB point below the reflectivity peak on the red side (longer wavelength side) of the grating larger than a value of 2/nm. The operating wavelength of the device may be tuned thermally, electrically, or thermo-electrically to be on the red side of the fiber Bragg grating reflectivity profile, preferably at the 3 dB point below the reflectivity peak or lower. In another embodiment, a second grating is formed on a second grating section of the waveguide on the opposite side of the gain section than the first grating section and wherein the reflectivity profile of the second grating overlaps at least a portion of the reflectivity profile of the first grating.

An optical apparatus includes a cooling device with a lower clad disposed thereon; a waveguide disposed on the lower clad and including an active waveguide to define a gain section and a passive waveguide to define a wavelength-tunable section; gratings disposed in the lower clad of the wavelength-tunable section; an upper clad disposed on the waveguide; a first upper electrode disposed on the upper clad of the gain section; and a second upper electrode disposed on the upper clad of the wavelength-tunable section. The lower clad of the wavelength-tunable section has a recess region to expose an upper surface of the cooling device, the recess region forming an air gap-having a height of 10 m to 80 m from the upper surface of the cooling device. The gratings are formed in a depth of at least 5 m from a bottom surface of the lower clad of the recess region.

An edge-emitting laser includes an active gain section and a reflector section optically coupled to the active gain section. The active gain section is configured to amplify an optical power of light across a wavelength range. The reflector section is configured to selectively reflect light of a selected wavelength within the wavelength range. The selected wavelength is tunable via high-frequency index modulation of the reflector section. The active gain section and the reflector section collectively form an optical cavity configured to lase coherent light in the selected wavelength.

A laser includes an active region surrounded by first and second waveguide layers. Two or more mask openings are formed within a dielectric layer on a surface parallel to the active region. A refractive grating is formed on the dielectric mask openings and includes three-dimensional grating features spaced apart in the light-propagation direction of the laser. The refractive grating provides modulation of a real part of the effective refractive index of the laser and modulation of the imaginary part is provided by modulation of the current flow through the mask openings.