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.

A nano-structured optical wavelength transmission filter is provided. The optical filter includes a patterned substrate on which a high refractive index dielectric waveguide is arranged. A low index dielectric layer is arranged on the high refractive index dielectric waveguide, on which an array of metallic nanostructures is arranged. The layers of the optical filter have conformal shapes defined by a patterned surface of the substrate. An optical filter system includes the optical transmission filter and a detector array fixed to the substrate. A spectrometer includes at least one optical transmission filter and/or at least one said optical transmission filter system, and has a spectral resolution of lower than 30 nm for incident light having a wavelength between 300 nm and 790 nm. A method of fabrication of an optical filter, an optical filter system and a spectrometer is also described.

Various embodiments relate to an optical detection element and GOI (Ge-on-insulator) device for ultra-small on-chip optical sensing, and a manufacturing method of the same. According to various embodiments, the optical detection element and the GOI device may be implemented on a GOI structure comprising a germanium (Ge) layer, and the GOI device may be implemented to have an optical detection element. Specifically, the GOI device may include a GOI structure with a waveguide region comprising a germanium layer, a light source element configured to generate light for the waveguide region, and at least one optical detection element configured to detect light coming from the waveguide region. At least one slot configured to collect light from the light source element may be formed in the germanium layer in the waveguide region. The light source element may generate light so as to be coupled to the germanium layer in the waveguide region. The optical detection element may detect heat generated as light is propagated from the germanium layer.

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.

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 light-receiving element, comprising a plurality of photodiodes formed by stacking in this sequence, a lower reflection mirror, a resonator including a photoelectric conversion layer, and an upper reflection mirror on a semiconductor substrate, wherein the plurality of photodiodes share the semiconductor substrate and the lower reflection mirror, the plurality of photodiodes includes a first photodiode having a resonance wavelength λ1 and a second photodiode having a resonance wavelength λ2 that is larger than the resonance wavelength λ1, and a reflectance of the lower reflection mirror has a first peak corresponding to the resonance wavelength λ1 and a second peak corresponding to the resonance wavelength λ2.

A photonic integrated circuit including an input for receiving input electromagnetic radiation having a bandwidth greater than 60 nm; a spectral splitter splitting the electromagnetic radiation into a plurality of spectral channels; a modulator for modulating an amplitude and a phase of one or more of the spectral channels so as to form modulated outputs; and a spectral recombiner for combining the modulated outputs into a single output port outputting output electromagnetic radiation having the desired output spectral intensity profile shaped by and synthesized from the modulated outputs.

An on-chip interferometer and a spectrometer including the interferometer are provided. An on-chip interferometer includes a waveguide for propagation of an optical signal including an input waveguide; at least two interferometer arms having one or more slot waveguides; and an output waveguide; wherein the input waveguide is split into the at least two interferometer arms which are recombined into the output waveguide; and a control mechanism configured for controlling a relative time delay between optical signals propagating in the two interferometer arms by modifying one or more slot widths of one or more of the slot waveguides; and wherein the relative time delay is at least 1, 2, 5, or at least 10 fs or at least one optical period of the longest optical wavelength of the optical signal.

The invention relates to a device for optical applications, which has an optical waveguide (10), to which a light source (11) can be connected. The optical waveguide (10) is designed in such a way that light emitted by the connectable light source (11) propagates along a light propagation axis (12). A wavelength-sensitive grating structure (13) in the optical waveguide (10) has detectors (20), which are arranged in such a way that the detectors absorb partial amounts of the light of the light source (11) that is scattered by the wavelength-sensitive grating structure (13). The grating structure (13) in the optical waveguide (10) is constructed of periodically arranged ellipsoid structural elements (14). The ellipsoid structural elements (14) have a different index of refraction than the material of the optical waveguide (10) surrounding the ellipsoid structural elements. The ellipsoid structural elements (14) have a longitudinal axis and a short axis, which are substantially perpendicular to the light propagation axis (12). Depending on the wavelength, partial amounts of the light scattered by the grating structure (13) are coupled out of the optical waveguide (10). The light hits the detectors (20). An absorbing or partially reflecting filter (30) is arranged between at least one of the detectors (20) and the optical waveguide (10). The detectors (20) have measuring elements for the intensity of the partial amount of the light that hits the detector (20) in question. An evaluation element is provided, which determines a wavelength from the intensity ratio of the plurality of detectors (20). The detectors (20) are arranged in such a way that the detectors either are arranged opposite each other on different sides of the long axes of the

An occupancy sensor covering a wide field in an integrated chip is disclosed. The occupancy sensor includes an array of grating coupled waveguide sensors wherein continuous wave (cw) signals monitor an ambient light field for dynamic changes on times scales of seconds, and high frequency signals map in three-dimensions of the space using time-of-flight (TOF) measurements, pixel level electronics that perform signal processing; array level electronics that perform additional signal processing; and communications and site level electronics that interface with actuators to respond to occupancy sensing.