An optical-coherence-tomography apparatus includes a light-source unit configured to emit light while changing a wavelength of the light; an optical interferometric system configured to split the light from the light-source unit into illuminating light to be applied to an object and reference light, and to generate interfering light from the illuminating light reflected by the object and the reference light; a photodetection unit configured to receive the interfering light, and an information-acquiring unit configured to acquire information on the object from the interfering light received by the photodetection unit. The light-source unit performs wavelength sweep by displacing a movable portion with an electrostatic force generated with the application of a voltage. The optical-coherence-tomography apparatus further includes a pull-in-detection unit configured to detect whether or not a pull-in effect is occurring on the movable portion of the light-source unit.

Described are various configurations of integrated wavelength lockers including asymmetric Mach-Zehnder interferometers (AMZIs) and associated detectors. Various embodiments provide improved wavelength-locking accuracy by using an active tuning element in the AMZI to achieve an operational position with high locking sensitivity, a coherent receiver to reduce the frequency-dependence of the locking sensitivity, and/or a temperature sensor and/or strain gauge to computationally correct for the effect of temperature or strain changes.

Described are various configurations of integrated wavelength lockers including asymmetric Mach-Zehnder interferometers (AMZIs) and associated detectors. Various embodiments provide improved wavelength-locking accuracy by using an active tuning element in the AMZI to achieve an operational position with high locking sensitivity, a coherent receiver to reduce the frequency-dependence of the locking sensitivity, and/or a temperature sensor and/or strain gauge to computationally correct for the effect of temperature or strain changes.

A pressure sensing device including a light source, at least one resonant structure, a cladding body, a first substrate and a second substrate is provided. The light source is configured to provide an original broadband light. The resonant structure includes a plurality of semiconductor rod structures arranged into a row at intervals along a single arranging direction, and each of the semiconductor rod structures has a lattice constant on the arranging direction. The original broadband light is transmitted between the semiconductor rod structures, and a resonant light is produced, wherein each of the semiconductor rod structures has a length perpendicular to the arranging direction and has a width parallel to the arranging direction, the length and the width are less than the wavelength of the resonant light. The cladding body completely covers the semiconductor rod structures of the at least one resonant structure. The cladding body and the at least one resonant structure are interposed between the first substrate and the second substrate. When a pressure is applied on at least one of the first substrate and the second substrate, the pressure is transmitted to the cladding body along a direction perpendicular to the arranging direction, a deformation corresponding to the pressure is occurred on the cladding body and the semiconductor rod structures on the arranging direction, and a wavelength of the resonant light is changed according to the deformation. Besides, a pressure sensing apparatus is also provided.

Methods for driving a tunable laser with integrated tuning elements are disclosed. The methods can include modulating the tuning current and laser injection current such that the laser emission wavelength and output power are independently controllable. In some examples, the tuning current and laser injection current are modulated simultaneously and a wider tuning range can result. In some examples, one or both of these currents is sinusoidally modulated. In some examples, a constant output power can be achieved while tuning the emission wavelength. In some examples, the output power and tuning can follow a linear relationship. In some examples, injection current and tuning element drive waveforms necessary to achieve targeted output power and tuning waveforms can be achieved through optimization based on goodness of fit values between the targeted and actual output power and tuning waveforms.

A movable diffraction grating includes: a support portion; a movable portion swingably connected to the support portion; a coil buried in the movable portion; a magnetic field generator configured to apply a magnetic field to the coil; an insulation layer provided on a surface of the movable portion; a resin layer provided on the insulation layer and provided with a diffraction grating pattern; and a reflection layer formed of a metal and provided on the resin layer to follow the diffraction grating pattern.

A semiconductor laser oscillator includes laser diode modules. A temperature sensor directly or indirectly detects a temperature of at least one of the laser diode modules. A collimating lens collimates respective lasers emitted from the laser diode modules. A grating performs spectrum beam coupling for the lasers emitted from the collimating lens. An incident angle varying mechanism changes incident angles of the respective lasers, at which the lasers emitted from the collimating lens are incident onto the grating in response to the temperature detected by the temperature sensor.

A semiconductor device includes a mesa structure having vertical sidewalls, the mesa structure including an active area comprising a portion of its height. A stressed passivation liner is formed on the vertical sidewalls of the mesa structure and over the portion of the active area. The stressed passivation liner induces strain in the active area to permit tuning of performance parameters of the mesa structure.

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.

Described herein is a fiber laser coupler, comprising a fiber laser cable enclosed in a housing, the housing includes a circuit and a temperature sensitive variable resistance element (TSVRE) coupled to the circuit, wherein the TSVRE is in thermal contact with one or more locations within the housing and is configured to provide a resistance in the circuit associated with a temperature of the TSVRE, wherein the circuit is further configured to couple to a processor configured to determine a temperature of the TSVRE based on reading the resistance in the circuit.