Embodiments are disclosed relating to a refractively-scanning interferometer comprising an aperture that receives an incident light beam at a receiving angle, a beam splitter configured to split the incident light beam into a first beam and a second beam, a first and a second reflector arranged to reflect the first beam and second beam, respectively, towards a combining optical element, and a refractive Optical Path Difference (rOPD) assembly interposed between the beam splitter and the first reflector, wherein the rOPD Assembly refracts the first light beam an even number of times with induced phase discrepancy being a vector sum of a first phase discrepancy induced by a first refraction and a second phase discrepancy induced by a second refraction, the rOPD Assembly being configured such that the first phase discrepancy is substantially opposite in direction to the second phase discrepancy, a portion of the first and second phase discrepancies cancelling one another out to decrease magnitude of the phase discrepancy.

A system including an optical transmitter. In some embodiments, the system includes: a first array of lasers; a first wavelength multiplexer, connected to the first array of lasers; a first coupler, connected to the wavelength multiplexer; and a first wavelength meter, connected to a first output of the first coupler.

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.

Embodiments are disclosed relating to a refractively-scanning interferometer comprising an aperture that receives an incident light beam at a receiving angle, a beam splitter configured to split the incident light beam into a first beam and a second beam, a first and a second reflector arranged to reflect the first beam and second beam, respectively, towards a combining optical element, and a refractive Optical Path Difference (rOPD) assembly interposed between the beam splitter and the first reflector, wherein the rOPD Assembly refracts the first light beam an even number of times with induced phase discrepancy being a vector sum of a first phase discrepancy induced by a first refraction and a second phase discrepancy induced by a second refraction, the rOPD Assembly being configured such that the first phase discrepancy is substantially opposite in direction to the second phase discrepancy, a portion of the first and second phase discrepancies cancelling one another out to decrease magnitude of the phase discrepancy.

A laser detection system and method of two way communication comprising: a Mach Zehnder interferometer, the Mach Zehnder interferometer comprising: an entry beam splitter for splitting incident light into a first arm, having an arm length L1 and a second arm having an arm length L2; a modulation stage for receiving a modulation signal and applying a phase difference to the second arm, the magnitude of the phase difference depending upon the magnitude of the modulation signal; an exit beam splitter for recombining light from the first arm with light from the second arm to create a first output and a second output; a detection stage comprising a first detector at the first output for detecting intensity modulation caused by interference of the recombined light; and a signal processor communicably connected to both the modulation stage and the detection stage.

Conventionally, wavelength locking and monitoring has been achieved used various components, including calibrated etalon filters, gratings, and arrays of color filters, which offer fairly bulky solutions that require complicated controls. An improved on-chip wavelength monitor comprises: a combination comb filter comprising a plurality of comb filters, each for receiving a test beams, and each comb filter including a substantially different FSR, e.g. 10 to 20 the next closest FSR. A controller dithers a phase tuning section of each comb filter to generate a maximum or minimum output in a corresponding photodetector indicative of the wavelength of the test signal.

A multi-channel sensing system is disclosed. The multi-channel sensing system includes a multi-channel sensor connector that wavelength-divides an optical pulse output from a pulsed laser into a plurality of channels in a spectrum domain, transmits each of a plurality of optical sub-pulses generated from the wavelength division to a channel path allocated for each channel in multi-channel paths, multiplexes the plurality of optical sub-pulses passed through the multi-channel paths and outputs an optical signal including the multiplexed optical sub-pulses; and a multi-channel optical phase detector that receives the optical signal output from the multi-channel connector and a reference signal which is synchronized to the pulse laser, and detects a channel-specific electrical signal that corresponds to a timing error between each of the plurality of optical sub-pulses included in the optical signal and the reference signal. At lease one of sensors is connected to at least one of the multi-channel paths.

Conventionally, wavelength locking and monitoring has been achieved used various components, including calibrated etalon filters, gratings, and arrays of color filters, which offer fairly bulky solutions that require complicated controls. An improved on-chip wavelength monitor comprises: a combination comb filter comprising a plurality of comb filters, each for receiving a test beams, and each comb filter including a substantially different FSR, e.g. 10 to 20 the next closest FSR. A controller dithers a phase tuning section of each comb filter to generate a maximum or minimum output in a corresponding photodetector indicative of the wavelength of the test signal.

A method and system are for expanding a measuring range of a Mach-Zehnder sensor based on the calculation of optical length; the method includes: (1) performing calibration according to a known parameter to complete calibration of a Mach-Zehnder pressure sensor; and (2) for an unknown parameter, testing the unknown parameter first using the Mach-Zehnder sensor to acquire discrete data; processing the discrete data using a peak and valley synthesis algorithm to restore a diffraction order m; calculating an optical length value of the unknown parameter; and restoring, according to a calibrated relationship curve between the optical length and the parameter, the unknown parameter, thus expanding the measuring range of the Mach-Zehnder sensor to enable the Mach-Zehnder sensor to break through the limitation of the FSR and the spectral width of a light source. The measuring range can be theoretically expanded to infinitely great.

An apparatus includes a photonic integrated circuit (PIC) to measure an optical wavelength of a light source. The PIC includes an optical splitter, a plurality of tunable interferometers and one or more detectors. The optical splitter is coupled to the light source, and the interferometers are coupled to the optical splitter. Each interferometer receives a portion of an optical signal of the light source. One or more detectors are coupled to each interferometer, and the interferometers have different free spectral ranges (FSRs). A largest FSR value of the different FSRs is greater than an entire intended wavelength measurement range of the PIC.