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.

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.

Described herein are optical sensing devices for photonic integrated circuits (PICs). A PIC may comprise a plurality of waveguides formed in a silicon on insulator (SOI) substrate, and a plurality of heterogeneous lasers, each laser formed from a silicon material of the SOI substrate and to emit an output wavelength comprising an infrared wavelength. Each of these lasers may comprise a resonant cavity included in one of the plurality of waveguides, and a gain material comprising a non-silicon material and adiabatically coupled to the respective waveguide. A light directing element may direct outputs of the plurality of heterogeneous lasers from the PIC towards an object, and one or more detectors may detect light from the plurality of heterogeneous lasers reflected from or transmitted through the object.

Structures for a photonics chip, testing methods for a photonics chip, and methods of forming a structure for a photonics chip. A photonics chip includes a first waveguide, a second waveguide, an optical tap coupling the first waveguide to the second waveguide, and a photodetector coupled to the second waveguide. A laser is attached to the photonics chip. The laser is configured to generate laser light directed by the first waveguide to the optical tap.

An integrated photonic device may include an image detector that comprises an array of pixels. The device may further include an integrated waveguide and a light coupler comprising a light receiving part optically coupled to the integrated waveguide for receiving a light signal. The light coupler may be adapted for coupling a same predetermined spectral band of the light signal to each of a plurality of pixels of the image detector. The light coupler may include a tapered portion, in which the light coupler tapers outward in a direction of propagation, and an end part comprising an elliptically shaped back reflector for reflecting light propagating along the direction of propagation back through the light coupler toward the integrated waveguide.

The present invention provides a method for measuring an optical sensor system comprising an array of intrinsic fiber optic sensors at an interrogator comprising an optical source and an optical detector. The method comprises the steps of emitting an optical signal to an array of intrinsic fiber optic sensors; detecting optical responses to the emitted signal from the sensors; associating each detected optical response with an individual sensor by determining within which region among a plurality of detection regions assigned to the individual sensors the optical response is detected wherein each detection region corresponds to a wavelength range in the bandwidth of the optical sensor system; and performing signal processing on each optical response to measure the value of the physical parameter detected by its associated sensor. A calibration of the detection region assigned to each sensor is performed at predetermined intervals.

A monitoring system includes an array of optical sensors disposed within a transformer tank. Each optical sensor is configured to have an optical output that changes in response to a temperature within the transformer tank. An analyzer is coupled to the array of optical sensors. The analyzer is configured to determine a sensed temperature distribution based on the sensed temperature. The sensed temperature distribution is compared to an expected distribution. Exterior contamination of the transformer tank is detected based on the comparison.

The present invention relates to an apparatus for optical applications, a spectrometer system and method for producing an apparatus for optical applications, and in particular to an apparatus comprising an optical waveguide having a first refractive index along a light propagation axis interrupted by a plurality of scattering portions having a second refractive index. Each scattering portion has a long axis substantially perpendicular to the light propagation axis as well as a short axis substantially perpendicular to the light propagation axis and the long axis. A receiver unit or a transmitter unit is arranged on a side of the optical waveguide, the long axis being substantially perpendicular, i.e. normal to the plane of this side on which the receiver unit or transmitter unit is arranged. Accordingly, simplification and miniaturization of an optical apparatus can be realized.

The pulse width of light from a pulsed light source 1 is stretched by a stretching element 2 such that an elapsed time and the wavelength of the light in the pulsed light correspond to each other on a one-to-one basis, and the stretched light radiates to an object S. The output of a light receiver 4 that has received light from the object S is digitized by an AD converter 6 and the digitized signal is supplied to a calculation means 5. A trigger signal generated by a trigger signal generator 7 in response to the rise of the pulsed light is delayed by a trigger delay section 74 and supplied to the AD converter 6 after the completion of a dead time T3.

A wavelength checker includes an optical converter composed of a conversion material that converts infrared light into visible light. The optical converter is disposed, on an output side (side from which light is output to an external space) of a plurality of first output waveguides of an optical waveguide chip, to receive emitted light that is guided through the first output waveguides and reflected on and emitted from the light emitting-side end surface. The light emitting-side end surface is a reflection surface that is inclined to face a main substrate.