An electro-optical modulating device and method that provides efficient control of the nonlinear propagation constant in an optical waveguide are featured. The electro-optical modulating device provides large wavelength tunability of the generated entangled photon pairs in real-time by using an applied external bias voltage. The electro-optical modulating device uses gate-tunable material at locations near the optical waveguide. The application of an external bias voltage creates a variable field-effect which in turn varies the optical dielectric properties of the waveguide. The result is a compact active, highly efficient wavelength-tunable integrated quantum photonic device for tunable entangled photon pair generation using an external bias voltage.

A method for growing a strontium tetraborate (SrB4O7) crystal is provided. The method includes lowering a seed crystal into a melt having a mixture comprising a source of Sr, B, O, and Cl. The method also includes heating and melting the mixture to a temperature sufficient to form a strontium tetraborate crystal.

A cw terahertz image beam is upconverted by a nonlinear optical process (e.g., sum- or difference-frequency generation with a near IR cw upconverting beam). The upconverted image is acquired by a near IR image detector. The bandwidths and center wavelengths of the terahertz image beam and the upconverting beam are such that wavelength filtering can be employed to permit an upconverted image beam to reach the detector while blocking or substantially attenuating the upconverting beam.

Provided is an optical parametric oscillation laser based on I-type quasi-phase matching. The optical parametric oscillation laser comprises a femtosecond laser pumping source (1), an input coupling mirror (3), an Mg:PPLN crystal (4), an output coupling mirror (7) and a beam splitter prism (12), wherein the femtosecond laser pumping source (1) of a synchronous pump, the input coupling mirror (3), the Mg:PPLN crystal (4), the output coupling mirror (7) and the beam splitter prism (12) are sequentially placed. Group velocity mismatching between near-infrared pump light and intermediate infrared signal light in the intermediate infrared optical parametric oscillation laser is eliminated by using the dispersion relationship between the crystal and the temperature and in a manner of adjusting the working temperature of the crystal, so that an optical parametric oscillation process can satisfy phase matching and group velocity matching at the same time, and therefore intermediate infrared ultrashort pulse laser with high power and wide spectrum is obtained.

A nonlinear wave mixing system with grating assisted phase matching is provided. The system includes a pump laser and a nonlinear waveguide. The pump laser is used to generate pump light at a select wavelength. The nonlinear waveguide is configured to generate produced light from the pump light that is directed into the nonlinear waveguide. The nonlinear waveguide includes at least one backward grating that is configured to diffract the produced light in a backward direction relative to a direction the produced light travels in the nonlinear waveguide to reach the backward grating. The backward grating having a grating momentum that generates counter-propagating phase matching in the produced light.

A device useful as a spectrometer or a sensor, comprising a source of a short electromagnetic pulses at a first wavelength and having a full width at half maximum in a range of 1 femtosecond-1 nanosecond; a sample holder in which the short pulses interact with the sample in the sample holder so as to form an output signal comprising a background residual of the short pulses and a sample response signal in the time domain, and an amplifier comprising nonlinear medium. The nonlinear medium comprises an input for receiving the output signal and a pump pulse at a second wavelength, and a second-order nonlinearity configured for a nonlinear process selectively amplifying the sample response signal, for example by temporally overlapping the pump pulse and the sample response signal.

An optical parametric device (OPD), which is selected from an optical parametric oscillator (OPO) or optical parametric generator (OPG), is configured with a nonlinear optical element (NOE) which converts an incoupled pump radiation at first frequency into output signal and idler radiations at one second frequency or different second frequencies, which is/are lower than the first frequency, by utilizing nonlinear interaction via a random quasi-phase matching process (RQPM-NOE). The NOE is made from a nonlinear optical material selected from optical ceramics, polycrystals, micro and nanocrystals, colloids of micro and nanocrystals, and composites of micro and nanocrystals in polymer or glassy matrices. The nonlinear optical material is prepared by modifying a microstructure of the initial sample of the NOE such that an average grain size is of the order of a coherence length of the three-wave interaction which enables the highest parametric gain achievable via the RQPM process.

A wavelength conversion apparatus according to an aspect of the present disclosure is a wavelength conversion apparatus that performs wavelength conversion of light through a non-linear crystal and including a first non-linear crystal, a container in which the first non-linear crystal is housed, a crystal holding member provided inside the container for fixing the first non-linear crystal, a first window provided to the container for guiding light to the first non-linear crystal from outside of the container, a second window provided to the container for guiding light output from the first non-linear crystal to outside of the container, a first heater provided inside the container for heating the first non-linear crystal, a battery that supplies electric power to the first heater, and a first controller that controls electric power supply to the first heater.

A mid-infrared upconversion imaging method and a mid-infrared upconversion imaging device are provided, which are used for imaging detection in a mid-infrared wavelength band, and related to a technical field of infrared imaging. The method includes directing pump laser and mid-infrared light into a chirped crystal component located in an optical cavity to obtain visible light; and imaging an object with the visible light.

A device including a photonic integrated circuit comprising one or more OPOs each comprising: an input configured to receive a pump wave comprising pulses or a frequency comb with a pump repetition rate, one or a plurality of nonlinear sections as part of a resonator or coupled to a resonator having a free spectral range, where at least one of the free spectral range or one of its harmonics is matched to the pump repetition rate or its harmonics, and one or a plurality of outputs configured to extract a portion of the waves generated by the OPO in response to the pump wave and/or the pump wave.