A light detection device includes: a Fabry-Perot interference filter provided with a light transmission region; a light detector configured to detect light transmitted through the light transmission region; a package having an opening and accommodating the Fabry-Perot interference filter and the light detector; and a light transmitting unit arranged on an inner surface of the package so as to close an opening, the light transmitting unit including a band pass filter configured to transmit light incident on the light transmission region. When viewed from a direction parallel to the line, an outer edge of the Fabry-Perot interference filter is positioned outside an outer edge of the opening, and an outer edge of the light transmitting unit is positioned outside the outer edge of the Fabry-Perot interference filter.

A light detection device includes: a Fabry-Perot interference filter provided with a light transmission region; a light detector configured to detect light transmitted through the light transmission region; a package having an opening and accommodating the Fabry-Perot interference filter and the light detector; and a light transmitting unit arranged on an inner surface of the package so as to close an opening, the light transmitting unit including a band pass filter configured to transmit light incident on the light transmission region. When viewed from a direction parallel to the line, an outer edge of the Fabry-Perot interference filter is positioned outside an outer edge of the opening, and an outer edge of the light transmitting unit is positioned outside the outer edge of the Fabry-Perot interference filter.

A camera includes one or more spectral illuminators, a tunable optical filter optically intermediate the one or more spectral illuminators and a scene, and a sensor array. The one or more spectral illuminators are configured to emit active spectral light. The tunable optical filter is dynamically adjustable to change a selected sub-band of the active spectral light that illuminates the scene. The sensor array includes a plurality of sensors each configured to measure spectral light reflected from the scene in the selected sub-band.

A Fourier-transform interferometer includes a phase change plate including a reflective layer configured to reflect a first light that is incident, and a meta surface configured to locally and differently change a phase of the first light that is reflected. The Fourier-transform interferometer further includes a photodetector configured to detect a second light, and a transflective mirror and a mirror configured to transmit a first part of a third light that is incident, to the phase change plate, transmit a remaining part of the third light, to the photodetector, and transmit the first light of which the phase is locally and differently changed, to the photodetector. The photodetector is further configured to detect an interference pattern between the remaining part of the third light and the first light of which the phase is locally and differently changed.

A Fourier-transform interferometer includes a phase change plate including a reflective layer configured to reflect a first light that is incident, and a meta surface configured to locally and differently change a phase of the first light that is reflected. The Fourier-transform interferometer further includes a photodetector configured to detect a second light, and a transflective mirror and a mirror configured to transmit a first part of a third light that is incident, to the phase change plate, transmit a remaining part of the third light, to the photodetector, and transmit the first light of which the phase is locally and differently changed, to the photodetector. The photodetector is further configured to detect an interference pattern between the remaining part of the third light and the first light of which the phase is locally and differently changed.

Provided is an optical device including a first wavelength variable interference filter in which a first reflective film and a second reflective film face each other with a first gap in between; a second wavelength variable interference filter in which a third reflective film and a fourth reflective film face each other with a second gap in between; and a first substrate having a transmissive property, which has a first surface and a second surface which is opposite in direction to the first surface, in which the second reflective film is provided on the first surface of the first substrate, and in which the third reflective film is provided on the second surface of the first substrate.

A system for optical linear sampling and coherent detection of an optical signal OS comprises a source emitting a pulsed optical signal SP and an optical coupler that splits the pulsed optical signal SP into two replicas, the first replica of the pulsed optical signal SP is sent to a first optical hybrid circuit and the second replica of the pulsed optical signal SP is send to a second optical hybrid circuit, a source emitting an optical signal OS and optical coupler that splits the incoming optical signal OS into two replicas, the first replica of the incoming optical signal OS is sent to the first optical hybrid circuit and the second replica of the incoming optical signal OS is sent to a wavelength recovery device WVLR, whose output is a continuous-waveform optical signal CW at the central wavelength of the incoming optical signal OS, which sends it to the second optical hybrid circuit. such that the optical signal OS is sampled within the first hybrid circuit and the continuous waveform optical signal CW is sampled in the second hybrid circuit, and a device BDADC comprising balanced photodectors detecting optical signals at the output of the two optical hybrid circuits and an analog/digital converter ADC.

An electro-optic element includes a first waveguide, which is a plasmonic waveguide, including a first core having a ferroelectric material and a cladding having a first cladding portion. The first cladding portion includes, at a first interface with the ferroelectric material, a first cladding material. The electro-optic element includes a first and a second electrode for producing an electric field in the ferroelectric material when a voltage is applied between the first and second electrodes, for modulating a real part of a refractive index of the ferroelectric material. The element includes, in addition, a crystalline substrate on which the ferroelectric material is epitaxially grown with zero or one or more intermediate layers present between the substrate and the ferroelectric material. The element may have a second waveguide, which is a photonic waveguide, including for enabling evanescent coupling between the first and second waveguides.

A tunable filter includes: a first transparent substrate including a first reflective surface; a second transparent substrate including a second reflective surface that opposes the first reflective surface; and a supporting member, connected to the first transparent substrate, that supports the second transparent substrate on the first transparent substrate so that the second reflective surface is disposed at a position separated from the first reflective surface in a normal direction of the first reflective surface. A cavity between the first reflective surface and the second reflective surface forms an etalon. A relative position of the second transparent substrate with respect to the first transparent substrate changes due to thermal expansion of the supporting member, and a length of the cavity changes in the normal direction.

In one aspect, an active hyperspectral filter array includes a polished wafer comprising a d33 material, wherein the d33 piezoelectric material is configured to display a piezoelectric effect along a same axis of a directed light used to obtain a controlled modulation; wherein the polished wafer comprises: a front electrode on a front surface of the polished wafer, a back electrode on a back surface of the polished wafer, wherein the front electrode and the back electrode are configured such that an optical path length is variable by application of an appropriate electric field.