A temperature compensation method for wavelength monitoring using spectrometers on photonic integrated chips and a related temperature-compensated wavelength monitoring device include an optical filter of the chip filters a source signal to provide at least one spectral reference line to a first spectrometer to detect thermal wavelength drifts thereof. At least one spectral line to be monitored is received by the same or another spectrometer of the chip to detect wavelength shifts thereof. The detected thermal drift of the reference line is compared to calibrated thermal drifts for the reference line which is associated with a calibrated thermal drift for the spectral response curve of the spectrometer receiving the spectral line to be monitored. A thermal drift rate for the response curve of the optical filter differs from a thermal drift rate for the response curve of the first spectrometer at least by an amount.

Methods for design and production of highly sensitive active and passive light detecting devices and systems. Orders of magnitude improvement in optical signal detection is made possible in high noise or low contrast scenes. The current invention creates a small spectral difference between two parts of a split light stream. When recombined, the altered light streams partially correlate, and that generates full amplitude signal oscillation at a frequency that depends on the constituent spectrum. The full amplitude signals and spectrum dependent oscillation make signal discrimination much better than intensity-only methods. The effect of read noise, amplifier noise, dark current noise, and thermal noise due to photo detector shunt resistance, become less important when compared to light detection using prior art methods

A system for stabilizing a scale factor associated with an optic rotation sensor comprises an optic rotation sensor that generates an optic signal in response to a rotation of the optic rotation sensor. A sensor detection system produces a rotation signal as a function of the optic signal and rotation of the optic rotation sensor. A first waveguide guides a portion of the optic signal for an interaction length, and produces a first processed optic signal. A second waveguide receives a portion of the optic signal from first waveguide through evanescent coupling, and produces a second processed optic signal. A wavemeter detector receives the optic signals and measures the effective interferometric wavelength (EIW) of the light based on the optic signals. A scale factor correction system receives the rotation signal and the EIW, and measures the correct rotation signal by processing the rotation signal and the EIW.

Methods for design and production of highly sensitive active and passive light detecting devices and systems. Orders of magnitude improvement in optical signal detection is made possible in high noise or low contrast scenes. The current invention creates a small spectral difference between two parts of a split light stream. When recombined, the altered light streams partially correlate, and that generates fall amplitude signal oscillation at a frequency that depends on the constituent spectrum. The full amplitude signals and spectrum dependent oscillation make signal discrimination much better than intensity-only methods. The effect of read noise, amplifier noise, dark current noise, and thermal noise due to photo detector shunt resistance, become less important when compared to light detection using prior art methods.

This disclosure is related to devices, systems, and techniques for precisely measuring a wavelength of an optical signal. For example, a wavemeter system includes processing circuitry, a detector array, a set of optical chips, and a coarse wavelength unit configured to generate a coarse wavelength measurement of the input optical signal. The processing circuitry is configured to select an optical chip from a plurality of optical chips. The detector array is configured to generate a partial interferogram based on the at least the portion of the input optical signal. The processing circuitry is further configured to calculate an optical spectrum of the input optical signal based on the partial interferogram corresponding to the at least the portion of the input optical signal and the calibration matrix and identify, based on the optical spectrum of the input optical signal, the precise wavelength of the input optical signal.

A method for fabricating a light receiving device includes: preparing a first substrate product which includes a semiconductor region having a common semiconductor layer, a first semiconductor laminate for a photodiode, a second semiconductor laminate for a waveguide, and a butt-joint between the first semiconductor laminate and the second semiconductor laminate, the first laminate and the second semiconductor laminate being disposed on the common semiconductor layer; etching the first substrate product with a first mask to form a second substrate product having a photodiode mesa structure produced from the first semiconductor laminate and a preliminary mesa structure produced from the second semiconductor laminate; etching the second substrate product with the first mask and a second mask, formed on the photodiode mesa structure; to produce a waveguide mesa structure from the preliminary mesa structure, and the waveguide mesa structure having a height larger than that of the preliminary mesa structure.

A method for fabricating a light receiving device includes: preparing a first substrate product which includes a semiconductor region having a common semiconductor layer, a first semiconductor laminate for a photodiode, a second semiconductor laminate for a waveguide, and a butt-joint between the first semiconductor laminate and the second semiconductor laminate, the first laminate and the second semiconductor laminate being disposed on the common semiconductor layer; etching the first substrate product with a first mask to form a second substrate product having a photodiode mesa structure produced from the first semiconductor laminate and a preliminary mesa structure produced from the second semiconductor laminate; etching the second substrate product with the first mask and a second mask, formed on the photodiode mesa structure; to produce a waveguide mesa structure from the preliminary mesa structure, and the waveguide mesa structure having a height larger than that of the preliminary mesa structure.

The present disclosure relates to an optical wavelength measuring device using an absorption-type optical fiber-based multiple optical fiber filter modules, an optical sensor system having the same, and an optical measurement method. The An optical wavelength measuring device includes a first optical splitter splitting the signal light provided from the optical fiber sensor into first and second split lights, a first optical detection unit detecting the first split light output from the first optical splitter, a polarization controller installed on an optical path of the second split light output from the first optical splitter, and controlling a polarization state of the second split light, a second optical detection unit detecting the second split light which is polarization-controlled by the polarization controller, and a calculation module calculating an optical wavelength of the signal light according to a physical quantity applied to the optical fiber sensor.

A system for stabilizing a scale factor associated with an optic rotation sensor comprises an optic rotation sensor that generates an optic signal in response to a rotation of the optic rotation sensor. A sensor detection system produces a rotation signal as a function of the optic signal and rotation of the optic rotation sensor. A first waveguide guides a portion of the optic signal for an interaction length, and produces a first processed optic signal. A second waveguide receives a portion of the optic signal from first waveguide through evanescent coupling, and produces a second processed optic signal. A wavemeter detector receives the optic signals and measures the effective interferometric wavelength (EIW) of the light based on the optic signals. A scale factor correction system receives the rotation signal and the EIW, and measures the correct rotation signal by processing the rotation signal and the EIW.

A device may include a first waveguide with an optical input at a first port. A device may include a second waveguide. A device may include a first coupler that optically couples the first waveguide to the second waveguide at a first position. A device may include a waveguide delay arm. A device may include a second coupler that optically couples the first waveguide to the second waveguide at a second position, the second position different from the first position.