The invention relates to a method for detecting the absolute temperature or temperature changes and/or the absolute wavelength or wavelength changes of an optical probe signal using an optical detection device including an optical waveguide structure defining an optical input port adapted to receive the optical probe signal and a first and a second optical output port adapted to output a first and a second optical detection signal, respectively. As a response to the optical probe signal, the optical waveguide structure being configured in such a way that a first power transfer function characterizing the transmission of the optical probe signal from the optical input port to the first optical output port differs, with respect to its wavelength and temperature dependency, from a second power transfer function characterizing the transmission of the optical probe signal from the optical input port to the second optical output port. The method includes the steps of transmitting the optical probe signal having a predetermined, but not necessarily constant, wavelength to the optical input port; detecting the first and second optical detection signal at the first and second optical output port by means of a first a and second opto-electrical converter which create a first and second electrical signal corresponding to the optical power of the respective first or second optical detection signal; measuring values of the first and second electrical signal and determining an absolute temperature value or a value of a temperature change of the optical waveguide structure and/or an absolute wavelength value or a value of a wavelength change of the optical probe signal by using the values measured of the first and second electrical signal and a first and a second previously determined wavelength and temperature dependency of both the first and second power transfer function. The invention further relates to an optical detection device for implementing this method.

Apparatus and associated methods relate to determining the wavelength of a narrow-band light beam. The narrow-band light beam is passed through an optical filter. The optical filter has complementary and monotonically-varying transmission and reflection coefficients within a predetermined band of wavelengths. The predetermined band of wavelengths includes the wavelength of the narrow-band light beam. A first photodetector detects amplitude of a first portion of the narrow-band light beam transmitted by the optical filter. A second photodetector detects amplitude of a second portion of the narrow-band light beam reflected by the optical filter. The wavelength of the narrow-band light beam is determined, based on a ratio of the determined amplitudes of the first and second portions of the narrow-band light beam transmitted and reflected, respectively.

A laser system comprising two phase-locked solid-state laser sources is described. The laser system can be phase-locked at a predetermined offset between the operating frequencies of the lasers. This is achieved with high precision while exhibiting both low noise and high agility around the predetermined offset frequency. A pulse generator can be employed to generate a series of optical pulses from the laser system, the number, duration and shape of which can all be selected by a user. A phase-lock feedback loop provides a means for predetermined frequency chirps and phase shifts to be introduced throughout a sequence of generated pulses. The laser system can be made highly automated. The above features render the laser system ideally suited for use within coherent control two-state quantum systems, for example atomic interferometry, gyroscopes, precision gravimeters gravity gradiometers and quantum information processing and in particular the generation and control of quantum bits.

There is described an interferometer for use in an optical locker. The interferometer comprises at least two transparent materials having different thermal path length sensitivities. The interferometer is configured such that an input beam is split by the interferometer into first and second intermediate beams, which recombine to form an output beam, the first and second intermediate beams travelling along respective first and second intermediate beam paths which do not overlap. At least one of the intermediate beam paths passes through at least two of the transparent materials. A length of each intermediate beam path which passes through each transparent material is selected such that an optical path difference between the first and second intermediate beam path is substantially independent of temperature.

A system for stabilizing a scale factor associated with an optic rotation sensor comprises an optic rotation sensor that generates an optic signal in response to a rotation of the optic rotation sensor. A sensor detection system produces a rotation signal as a function of the optic signal and rotation of the optic rotation sensor. A first waveguide guides a portion of the optic signal for an interaction length, and produces a first processed optic signal. A second waveguide receives a portion of the optic signal from first waveguide through evanescent coupling, and produces a second processed optic signal. A wavemeter detector receives the optic signals and measures the effective interferometric wavelength (EIW) of the light based on the optic signals. A scale factor correction system receives the rotation signal and the EIW, and measures the correct rotation signal by processing the rotation signal and the EIW.

Provided are various embodiments related to an electronic device. According to an embodiment, an electronic device may comprise: an IR (infrared light) transmission unit for outputting IR light; an IR reception unit for receiving IR light; and processor. The processor is configured to: identify a first IR transmission signal to be transmitted to an external device; identify a first time interval and a second time interval, which correspond to the first IR transmission signal; output first IR light corresponding to at least a part of the first IR transmission signal through the IR transmission unit in the first time interval; identify whether second IR light having the intensity larger than or equal to a threshold is received by the IR reception unit in the second time interval; and when the second IR light having the intensity larger than or equal to the threshold is received by the IR reception unit in the second time interval, interrupt transmission of the IR transmission signal. In addition, other embodiments may be possible.

A laser detection system and method of two way communication comprising: a Mach Zehnder interferometer, the Mach Zehnder interferometer comprising: an entry beam splitter for splitting incident light into a first arm, having an arm length L1 and a second arm having an arm length L2; a modulation stage for receiving a modulation signal and applying a phase difference to the second arm, the magnitude of the phase difference depending upon the magnitude of the modulation signal; an exit beam splitter for recombining light from the first arm with light from the second arm to create a first output and a second output; a detection stage comprising a first detector at the first output for detecting intensity modulation caused by interference of the recombined light; and a signal processor communicably connected to both the modulation stage and the detection stage.

There is described an interferometer for use in an optical locker. The interferometer comprises at least two transparent materials having different thermal path length sensitivities. The interferometer is configured such that an input beam is split by the interferometer into first and second intermediate beams, which recombine to form an output beam, the first and second intermediate beams travelling along respective first and second intermediate beam paths which do not overlap. At least one of the intermediate beam paths passes through at least two of the transparent materials. A length of each intermediate beam path which passes through each transparent material is selected such that an optical path difference between the first and second intermediate beam path is substantially independent of temperature.

A laser source may include a laser diode, a modulation device, and a feedback device. The modulation device may include an electric power source and may be suitable for modifying a current intensity applied to the laser diode, which may modify an emission frequency of the laser diode. The feedback device may be suitable for modifying a current intensity applied to the laser diode by the electric power source as a function of the electromagnetic radiation emitted by the laser diode.

An optical sensor module includes an interferometric sensor and a set of one or more optical elements. The interferometric sensor includes a coherent light source and at least one detector configured to generate an interferometric signal. The set of one or more optical elements is configured to simultaneously direct a first portion of light emitted by the coherent light source toward a first focus area within a first depth of focus; direct a second portion of the light emitted by the coherent light source toward a second focus area within a second depth of focus; and direct portions of the emitted light that are returned from one or more objects within the first depth of focus or the second depth of focus toward the interferometric sensor.