A method for generating frequency converted laser radiation is disclosed. The disclosure provides a method enabling generation of a frequency converted wavelength division multiplexed light source that is easy to implement at low cost. Adjustment of the center frequency and the mode spacing in a frequency converted wavelength division multiplexed light source is also disclosed. A related method of use discloses generating pump laser radiation through combination of multiple pump sources in a wavelength division multiplexed arrangement; passing the pump laser radiation through the non-linear medium of a singly resonant, single-frequency optical parametric oscillator, wherein the pump laser radiation is continuous wave or pulsed, wherein the pulse duration in the latter case is longer than the time the optical parametric oscillation requires to reach its steady state; and coupling out the non-resonant idler or signal laser radiation from the optical parametric oscillator as usable frequency converted laser radiation. Moreover, the invention relates to a laser device for carrying out the method of the invention.

A method for generating frequency converted laser radiation is disclosed. The disclosure provides a method enabling generation of a frequency converted wavelength division multiplexed light source that is easy to implement at low cost. Adjustment of the center frequency and the mode spacing in a frequency converted wavelength division multiplexed light source is also disclosed. A related method of use discloses generating pump laser radiation through combination of multiple pump sources in a wavelength division multiplexed arrangement; passing the pump laser radiation through the non-linear medium of a singly resonant, single-frequency optical parametric oscillator, wherein the pump laser radiation is continuous wave or pulsed, wherein the pulse duration in the latter case is longer than the time the optical parametric oscillation requires to reach its steady state; and coupling out the non-resonant idler or signal laser radiation from the optical parametric oscillator as usable frequency converted laser radiation. Moreover, the invention relates to a laser device for carrying out the method of the invention.

Systems and methods for measuring or inspecting semiconductor structures using broadband infrared radiation are disclosed. The system may include an illumination source comprising a pump source configured to generate pump light and a nonlinear optical (NLO) assembly configured to generate broadband IR radiation in response to the pump light. The system may also include a detector assembly and a set of optics configured to direct the IR radiation onto a sample and direct a portion of the IR radiation reflected and/or scattered from the sample to the detector assembly.

Systems and methods for measuring or inspecting semiconductor structures using broadband infrared radiation are disclosed. The system may include an illumination source comprising a pump source configured to generate pump light and a nonlinear optical (NLO) assembly configured to generate broadband IR radiation in response to the pump light. The system may also include a detector assembly and a set of optics configured to direct the IR radiation onto a sample and direct a portion of the IR radiation reflected and/or scattered from the sample to the detector assembly.

The present invention provides an optical phase synchronization method characterized by involving applying a small phase modulation signal (dither signal) to local oscillator light, acquiring an error signal that is dependent on a phase shift, and controlling the phase shift. The present invention further provides an optical phase synchronization method characterized by involving inducing a specific phase pattern in dummy pulses in an optical resonator using injection light, applying phase modulation to the local oscillator light, and thereby acquiring a part of the measurement result of the dummy pulses as the error signal. The present invention is further characterized by arranging calculation pulses and phase synchronization dummy pulses in a distributed manner (for example, alternately) and increasing a pulse width using a narrow band electrical filter.

The present invention provides an optical phase synchronization method characterized by involving applying a small phase modulation signal (dither signal) to local oscillator light, acquiring an error signal that is dependent on a phase shift, and controlling the phase shift. The present invention further provides an optical phase synchronization method characterized by involving inducing a specific phase pattern in dummy pulses in an optical resonator using injection light, applying phase modulation to the local oscillator light, and thereby acquiring a part of the measurement result of the dummy pulses as the error signal. The present invention is further characterized by arranging calculation pulses and phase synchronization dummy pulses in a distributed manner (for example, alternately) and increasing a pulse width using a narrow band electrical filter.

An entangled-photon pair emitting device according to an embodiment of the inventive concept includes a piezoelectric structure having a first surface and a second surface, which face each other, wherein the piezoelectric structure includes an opening passing through the piezoelectric structure from the first surface to the second surface, a stress transfer medium that fills the opening, a light source emitting part disposed on the stress transfer medium, an upper electrode disposed on the first surface of the piezoelectric structure, and a lower electrode disposed on the second surface of the piezoelectric structure. Here, the light source emitting part includes a semiconductor thin-film and a quantum dot in the semiconductor thin-film.

An entangled-photon pair emitting device according to an embodiment of the inventive concept includes a piezoelectric structure having a first surface and a second surface, which face each other, wherein the piezoelectric structure includes an opening passing through the piezoelectric structure from the first surface to the second surface, a stress transfer medium that fills the opening, a light source emitting part disposed on the stress transfer medium, an upper electrode disposed on the first surface of the piezoelectric structure, and a lower electrode disposed on the second surface of the piezoelectric structure. Here, the light source emitting part includes a semiconductor thin-film and a quantum dot in the semiconductor thin-film.

A nonlinear fiber interferometer is disclosed suitable for fiber sensor and other applications. A first nonlinear fiber section amplifies probe and conjugate sidebands of a pump through four-wave mixing. A second section introduces a phase shift to be measured, for example from a sensor. A third nonlinear fiber section amplifies with phase-sensitive gain to increase signal-to-noise ratio. Based on phase-sensitive output power of probe and/or conjugate components, the phase shift can be measured. Superior performance can be obtained by balancing gain between the (first and third) nonlinear sections. Non-fiber, for example photonic integrated circuit, embodiments are disclosed. Differential sensing, alternative detection schemes, sensing applications, associated methods, and other variations are disclosed.

A nonlinear fiber interferometer is disclosed suitable for fiber sensor and other applications. A first nonlinear fiber section amplifies probe and conjugate sidebands of a pump through four-wave mixing. A second section introduces a phase shift to be measured, for example from a sensor. A third nonlinear fiber section amplifies with phase-sensitive gain to increase signal-to-noise ratio. Based on phase-sensitive output power of probe and/or conjugate components, the phase shift can be measured. Superior performance can be obtained by balancing gain between the (first and third) nonlinear sections. Non-fiber, for example photonic integrated circuit, embodiments are disclosed. Differential sensing, alternative detection schemes, sensing applications, associated methods, and other variations are disclosed.