A tunable filter includes: a first transparent substrate including a first reflective surface; a second transparent substrate including a second reflective surface that opposes the first reflective surface; and a supporting member, connected to the first transparent substrate, that supports the second transparent substrate on the first transparent substrate so that the second reflective surface is disposed at a position separated from the first reflective surface in a normal direction of the first reflective surface. A cavity between the first reflective surface and the second reflective surface forms an etalon. A relative position of the second transparent substrate with respect to the first transparent substrate changes due to thermal expansion of the supporting member, and a length of the cavity changes in the normal direction.

An optical apparatus, comprising a semiconductor substrate, a dielectric layer located on the semiconductor substrate, wherein a membrane portion of the dielectric layer is located over a cavity in a surface of the semiconductor substrate, a resistive heater located on the membrane portion, the resistive heater being controllable by a current applied to the resistive heater and an etalon optical filter located on the resistive heater and over the cavity, an optical passband of the etalon optical filter being wavelength tunable by the resistive heater. A method of manufacturing the optical apparatus is also disclosed.

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 light source module (100) with integrated wavemeter components (460, 494, 495) for stabilizing the output power and wavelength of a superluminescent diode or other broadband semiconductor light source (121) outputting a broadband output beam. A portion of the source output beam is directed to an optical edge filter (460) with a cross-over wavelength lying within the bandwidth of the output beam. The edge filter (460) divides the light it receives into a short-wavelength component and a long-wavelength component. These two components are then directed onto respective photodetectors (494, 495) that output respective signals to a wavemeter controller. The controller adjusts the drive current and/or temperature of the source to maintain the mean wavelength of the source's output beam at a set constant value according to a control parameter determined from a combination of the photodetector signals such as their ratio or the ratio between their difference and sum.

The present invention involves a method of controlling at least one first element (22) for heating a multi-resonant optical device (10), automatically alternating between at least a first mode and a second mode, wherein, in the first mode, the first heating element is controlled by a first feedback loop (20) to lead the optical device to operate at a first resonance peak and wherein, at least during part of the second mode, the first feedback loop is made diverging to lead the optical device to operate at a second resonance peak.

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.

Various embodiments relate to polarization splitters. A polarization splitter may include a silicon nitride (SiN) waveguide core configured to receive an input light signal having a first polarization mode and a second polarization mode. The polarization splitter may further include a silicon (Si) slot waveguide core disposed proximate the SiN waveguide core. The Si slot waveguide core may include a tapered portion at a first end configured to couple the first polarization mode to the Si slot waveguide.

In an example, a system comprises a first optical device, a second optical device, and an optical modulator. The first optical device, in a non-cryogenic environment, receives a light signal, outputs the light signal, receives a first modulated light signal, and outputs the first modulated light signal into the non-cryogenic environment. The second optical device, in a cryogenic environment, receives the light signal from the first optical device, outputs the light signal, receives the first modulated light signal, and outputs the first modulated light signal. The optical modulator, in the cryogenic environment, receives the light signal from the second optical device, modulates the light signal to produce the first modulated light signal and a second modulated light signal, outputs the second modulated light signal, and outputs the first modulated light signal to the second optical device.

A pin hole or aperture is located or formed adjacent to the end surface of one or more of the input ports or fibers, or adjacent to one or more of the output ports or fibers, of a fiberoptic component. The aperture allows light to enter (or exit) the core of the associated fiber, and the non-transparent layer that surrounds the aperture blocks light from entering or exiting the cladding layer of the associated fiber. This blocking of the evanescent field in the cladding layer serves to reduce the polarization, wavelength, and temperature dependencies of the light coupling to the output port(s) or fiber(s) of the optical component. It can also reduce the passband width of the selected wavelength in tunable optical filter applications. The non-transparent layer surrounding the aperture can be made reflective, and light that is reflected by the non-transparent layer can be used for optical power monitoring.