A tunable laser includes a reflective silicon optical amplifier (RSOA) with a reflective end and an interface end and an array of narrow-band reflectors, which each have a different center wavelength. It also includes a silicon-photonic optical switch, having an input port and N output ports that are coupled to a different narrow-band reflector in the array of narrow-band reflectors. The tunable laser also includes an optical waveguide coupled between the interface end of the RSOA and the input of the silicon-photonic optical switch. The frequency of this tunable laser can be tuned in discrete increments by selectively coupling the input port of the silicon-photonic optical switch to one of the N output ports, thereby causing the RSOA to form a lasing cavity with a selected narrow-band reflector coupled to the selected output port. The tunable laser also includes a laser output optically coupled to the lasing cavity.

A terahertz quantum cascade laser device is provided comprising a substrate having a top substrate surface, a bottom substrate surface, and an exit facet extending between the top substrate surface and the bottom substrate surface at an angle θ.sub.tap. The device comprises a waveguide structure having a top surface, a bottom surface, a front facet extending between the top surface and the bottom surface and positioned proximate to the exit facet, and a back facet extending between the top surface and the bottom surface and oppositely facing the front facet. The waveguide structure comprises a quantum cascade laser structure configured to generate light comprising light of a first frequency ω.sub.1, light of a second frequency ω.sub.2, and light of a third frequency ω.sub.THz, wherein ω.sub.THz=ω.sub.1−ω.sub.2; an upper cladding layer; and a lower cladding layer. The device comprises a distributed feedback grating layer configured to provide optical feedback for one or both of the light of the first frequency ω.sub.1 and the light of the second frequency ω.sub.2 and to produce lasing at one or both of the first frequency ω.sub.1 and the second frequency ω.sub.2, thereby resulting in laser emission at the third frequency ω.sub.THz at a Cherenkov angle θ.sub.THz through the bottom surface of the waveguide structure into the substrate and exiting the substrate through the exit facet. The device comprises a high-reflectivity coating on the front facet of the waveguide structure.

A variable wavelength light source and an apparatus including the same are disclosed. The variable wavelength light source includes: a first waveguide; a second waveguide spaced apart from the first waveguide; a first optical amplifier including a first gain medium; and a second optical amplifier including a second gain medium that is different from the first gain medium.

A white light spectroscopy system includes a super continuum light source having an input light source including semiconductor diodes to generate an input beam having a wavelength shorter than 2.5 microns. The light source includes a cladding-pumped fiber optical amplifier to receive the input beam, and a photonic crystal fiber to receive the amplified optical beam to broaden the spectral width to 100 nm or more forming an output beam in the visible wavelength range. The output beam is pulsed with a repetition rate of 1 Megahertz or higher. The system also includes a lens and/or mirror to receive the output beam, to send the output beam to a scanning stage, and to deliver the received output beam to a sample. A detection system includes dispersive optics and narrow band filters followed by one or more detectors to permit approximately simultaneous measurement of at least two wavelengths from the sample.

The disclosed embodiments provide a tunable laser that includes a set of M reflective silicon optical amplifiers (RSOAs) and a set of N narrow-band reflectors. It also includes a silicon-photonic optical switch, having M amplifier ports, which are coupled through a set of M optical waveguides to the set of M RSOAs, and N reflector ports, which are coupled to the set of N narrow-band reflectors. The tunable laser also includes a switching mechanism that facilitates coupling at least one selected amplifier port from the M amplifier ports with a selected reflector port from the N reflector ports, thereby causing an RSOA coupled to the selected amplifier port to form a lasing cavity with a narrow-band reflector coupled to the selected reflector port. The tunable laser also includes a laser output, which is optically coupled to the lasing cavity.

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.

A light source based on an optical frequency mixer is disclosed. The light source has a first laser for emitting light at a first optical frequency, and a plurality of second lasers for emitting light at different second optical frequencies. The optical frequency mixer provides output light beams at mixed optical frequencies of the first and second lasers. Wavelength of output light beams may be tuned by tuning wavelength of any of the first or second lasers. In this manner, RGB wavelength-tunable light sources may be constructed based on red or near-infrared lasers. The wavelength tunability of the output light beams may be used to angularly scan or refocus the light beams.

An example system for inspecting a surface includes a laser, an optical system, a gated camera, and a control system. The laser is configured to emit pulses of light, with respective wavelengths of the pulses of light varying over time. The optical system includes at least one optical element, and is configured to direct light emitted by the laser to points along a scan line one point at a time. The gated camera is configured to record a fluorescent response of the surface from light having each wavelength of a plurality of wavelengths at each point along the scan line. The control system is configured to control the gated camera such that an aperture of the gated camera is open during fluorescence of the surface but closed during exposure of the surface to light emitted by the laser.

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.

The present disclosure pertains to a light source for a time-of-flight device having a vertical-cavity surface-emitting laser. The vertical-cavity surface-emitting laser has a liquid crystal section for providing light generated by the vertical-cavity surface-emitting laser at two or more distant wave-lengths.