Methods and apparatus for receiving a return laser pulse at a detector system having pixels in a pixel array and analyzing a response of the pixels in the pixel array including comparing the response to at least one threshold corresponding to decay of photonic energy of the laser pulse over distance and target reflectivity, wherein the at least one threshold comprises a first threshold corresponding to a low trigger for a pulse generated by a first type of laser and a second threshold corresponding to a high trigger for the pulse generated by the first type of laser. Embodiments can further include generating an alert signal based on the response of the pixels in the pixel array.

Building blocks are provided for on-chip chemical sensors and other highly-compact photonic integrated circuits combining interband or quantum cascade lasers and detectors with passive waveguides and other components integrated on a III-V or silicon. A MWIR or LWIR laser source is evanescently coupled into a passive extended or resonant-cavity waveguide that provides evanescent coupling to a sample gas (or liquid) for spectroscopic chemical sensing. In the case of an ICL, the uppermost layer of this passive waveguide has a relatively high index of refraction that enables it to form the core of the waveguide, while the ambient air, consisting of the sample gas, functions as the top cladding layer. A fraction of the propagating light beam is absorbed by the sample gas if it contains a chemical species having a fingerprint absorption feature within the spectral linewidth of the laser emission.

A safety assembly for use with a laser-directed energy weapon is disclosed. The assembly comprises a control system comprising a photodetector and a processing unit; and an optical device configured to attach to a target such that, when attached, the optical device provides a light beam to the photodetector. The processing unit is arranged to compare the received light beam against one or more predetermined attributes, and to permit the laser-directed energy weapon to fire only when the received light beam is determined to have the one or more attributes.

Disclosed is an optical sensor, including an external cavity laser configured to output sensing light and reference light; and a photodetector configured to detect a beating signal by an interference of the sensing light and the reference light output from the external cavity laser, in which the external cavity laser includes a reflecting filter including a sensing grating, to which a sensing object is attachable, and a reference grating, which is disposed on the same plane as that of the sensing grating, and outputs sensing light reflected from the sensing grating and reference light reflected from the reference grating. Accordingly, the optical sensor does not require a high-resolution spectroscope and has improved resolution and sensitivity.

A sensor system includes a self-mixing interferometry sensor; a drive circuit configured to apply a modulated drive signal to an input of the self-mixing interferometry sensor; a mixer circuit configured to mix a modulated output of the self-mixing interferometry sensor with a local oscillator signal that is orthogonal to the modulated drive signal over a period of time; an integrator circuit configured to integrate an output of the mixer circuit over the period of time; and a processor configured to determine, using an output of the integrator circuit, at least one of a round-trip propagation time of electromagnetic radiation emitted by the self-mixing interferometry sensor and reflected back into the self-mixing interferometry sensor by an object or medium, or a velocity of the object or medium.

A method for producing an integrated micromechanical fluid sensor component includes forming a first wafer with a first Bragg reflector and with a light-emitting device on a first substrate. The light-emitting device is configured to emit light rays in an emission direction from a surface of the light-emitting device facing away from the first Bragg reflector. The method further includes forming a second wafer with a second Bragg reflector and with a photodiode on a second substrate. The photodiode is arranged on a surface of the second Bragg reflector facing towards the second substrate. The method also includes bonding or gluing the first wafer to the second wafer such that there is formed a cavity into which a fluid is introduced and through which the light rays can pass. The method further includes separating the fluid sensor component from the first and the second wafer.

Provided is a biosensor. The biosensor includes a substrate, an optical structure provided on the substrate, and a cover provided on the substrate and having a bridge shape that is in contact with a top surface of the substrate at both sides of the optical structure. The cover has a channel extending in a first direction, the optical structure is provided inside the channel, and the optical structure is configured to capture biomaterials that travel through the channel.

A laser diode includes a semiconductor structure of a lower Bragg reflector layer, an active region, and an upper Bragg reflector layer. The upper Bragg reflector layer includes a lasing aperture having an optical axis oriented perpendicular to a surface of the active region. The active region includes a first material, and the lower Bragg reflector layer includes a second material, where respective lattice structures of the first and second materials are independent of one another. Related laser arrays and methods of fabrication are also discussed.

Building blocks are provided for on-chip chemical sensors and other highly-compact photonic integrated circuits combining interband or quantum cascade lasers and detectors with passive waveguides and other components integrated on a III-V or silicon. A MWIR or LWIR laser source is evanescently coupled into a passive extended or resonant-cavity waveguide that provides evanescent coupling to a sample gas (or liquid) for spectroscopic chemical sensing. In the case of an ICL, the uppermost layer of this passive waveguide has a relatively high index of refraction that enables it to form the core of the waveguide, while the ambient air, consisting of the sample gas, functions as the top cladding layer. A fraction of the propagating light beam is absorbed by the sample gas if it contains a chemical species having a fingerprint absorption feature within the spectral linewidth of the laser emission.

An optical proximity sensor includes a first vertical cavity surface-emitting laser configured for self-mixing interferometry to determine distance to and/or velocity of an object. The optical proximity sensor also includes a second vertical cavity surface-emitting laser configured for self-mixing interferometry to determine whether any variation in a fixed distance has occurred. The optical proximity sensor leverages output from the second vertical cavity surface-emitting laser to calibrate output from the second vertical cavity surface-emitting laser to eliminate and/or mitigate environmental effects, such as temperature changes.