Conformal imaging vibrometer using adaptive optics with scene-based wave front sensing. An extended object is located at the first end of a link, and a reference-free, adaptive optical, conformal imaging vibrometer using scene-based wave front sensing is located at the second end of the link. An aberrated, free space or guided-wave path exists between the ends of the link. The adaptive optical system compensates for path distortions. Using a single interrogation beam, whole-body vibrations of opaque and reflective objects can be probed, as well as transparent and translucent objects, the latter pair employing a Zernike heterodyne interferometer.

Conformal imaging vibrometer using adaptive optics with scene-based wave front sensing. An extended object is located at the first end of a link, and a reference-free, adaptive optical, conformal imaging vibrometer using scene-based wave front sensing is located at the second end of the link. An aberrated, free space or guided-wave path exists between the ends of the link. The adaptive optical system compensates for path distortions. Using a single interrogation beam, whole-body vibrations of opaque and reflective objects can be probed, as well as transparent and translucent objects, the latter pair employing a Zernike heterodyne interferometer.

Optical microcavity resonance measurements can have readout noise matching the fundamental limit set by thermal fluctuations in the cavity. Small-heat-capacity, wavelength-scale microcavities can be used as bolometers that bypass the limitations of other bolometer technologies. The microcavities can be implemented as photonic crystal cavities or micro-disks that are thermally coupled to strong mid-IR or LWIR absorbers, such as pyrolytic carbon columns. Each microcavity and the associated absorber(s) rest on hollow pillars that extend from a substrate and thermally isolate the cavity and the absorber(s) from the rest of the bolometer. This ensures that thermal transfer to the absorbers is predominantly from radiation as opposed to from conduction. As the absorbers absorb thermal radiation, they shift the resonance wavelength of the cavity. The cavity transduces this thermal change into an optical signal by reflecting or scattering more (or less) near-infrared (NIR) probe light as a function of the resonance wavelength shift.

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 laser system comprising two phase-locked solid-state laser sources is described. The laser system can be phase-locked at a predetermined offset between the operating frequencies of the lasers. This is achieved with high precision while exhibiting both low noise and high agility around the predetermined offset frequency. A pulse generator can be employed to generate a series of optical pulses from the laser system, the number, duration and shape of which can all be selected by a user. A phase-lock feedback loop provides a means for predetermined frequency chirps and phase shifts to be introduced throughout a sequence of generated pulses. The laser system can be made highly automated. The above features render the laser system ideally suited for use within coherent control two-state quantum systems, for example atomic interferometry, gyroscopes, precision gravimeters gravity gradiometers and quantum information processing and in particular the generation and control of quantum bits.

A laser system comprising two phase-locked solid-state laser sources is described. The laser system can be phase-locked at a predetermined offset between the operating frequencies of the lasers. This is achieved with high precision while exhibiting both low noise and high agility around the predetermined offset frequency. A pulse generator can be employed to generate a series of optical pulses from the laser system, the number, duration and shape of which can all be selected by a user. A phase-lock feedback loop provides a means for predetermined frequency chirps and phase shifts to be introduced throughout a sequence of generated pulses. The laser system can be made highly automated. The above features render the laser system ideally suited for use within coherent control two-state quantum systems, for example atomic interferometry, gyroscopes, precision gravimeters gravity gradiometers and quantum information processing and in particular the generation and control of quantum bits.

A method and a system for interrogating an optical fiber includes a probe signal that has a first frequency comb at a first repetition rate (Δf) injected into the optical fiber. A backscattering signal that includes the probe signal convolved with an impulse response of the optical fiber in reflection which is sensitive to at least one parameter being measured from the optical fiber is gathered. The backscattering signal is beaten with a local oscillator signal to generate a beating signal, the local oscillator signal including a second frequency comb at a second repetition rate that is offset from the first repetition rate (Δf+δf) and being mutually coherent with the first frequency comb. The resulting beating signal is analysed to thereby determine the at least one parameter being measured from the optical fiber.

A wavefront detector (100) and method for determining a signal wavefront (Ws) of a signal beam (Ls). A beam combiner (11) is configured to combine the signal beam (Ls) with a reference beam (Lr). An image detector (12) comprising an array of photosensitive pixels (12p) is configured to receive and measure an interference pattern (Wrs) of the combined signal and reference beams (Lr+Ls). A reference light source (14) is configured to generate the reference beam (Lr). A feedback controller (20) is configured to receive an interference signal (I.sub.B) based on measurement of at least part of the combined signal and reference beams (Lr+Ls), and control generation of the reference beam (Lr) by a feedback loop based on the interference signal (I.sub.B).

A wavefront detector (100) and method for determining a signal wavefront (Ws) of a signal beam (Ls). A beam combiner (11) is configured to combine the signal beam (Ls) with a reference beam (Lr). An image detector (12) comprising an array of photosensitive pixels (12p) is configured to receive and measure an interference pattern (Wrs) of the combined signal and reference beams (Lr+Ls). A reference light source (14) is configured to generate the reference beam (Lr). A feedback controller (20) is configured to receive an interference signal (I.sub.B) based on measurement of at least part of the combined signal and reference beams (Lr+Ls), and control generation of the reference beam (Lr) by a feedback loop based on the interference signal (I.sub.B).

Disclosed is a phase shift measuring device, which includes a dual mode laser including a first beat light source generating a first beating signal and a second beat light source generating a second beating signal, and that outputs a dual mode signal including the first beating signal and the second beating signal, a first splitter that receives the dual mode signal to generate a first branch signal and a second branch signal, the first branch signal and the second branch signal being including the branched first beating signal and the branched second beating signal, respectively, a phase control unit that receives the first branch signal and to generate a combined signal, a transmitting end that receives the combined signal from the phase control unit and generates a transmission signal based on the combined signal, and a receiving end.