Information relating to an etalon is accessed, the etalon being associated with a calibration parameter having a pre-set default value, the etalon being configured to produce an interference pattern including a plurality of fringes from a received light beam, and the information relating to the etalon including first spatial information related to a first fringe of the plurality of fringes and second spatial information related to a second fringe of the plurality of fringes. A first wavelength value of the received light beam is determined based on the spatial information related to the first fringe and an initial value of the calibration parameter. A second wavelength value of the received light beam is determined based on the spatial information related to the second fringe and the initial value of the calibration parameter. The first wavelength value and the second wavelength value are compared to determine a measurement error value.

There is provided a method, apparatus and system for calibrating and operating an optical wavemeter. In calibration, training optical signals with known wavelengths are input to a wavemeter, and corresponding photodetector measurements are obtained. Optical parameters of the wavemeter are then estimated based on the measurements. The optical parameters are indicative of a length difference ΔL between two unequal-length waveguides in an optical delay line of the wavemeter; and scattering parameters of a multi-mode interferometer (MMI) coupler of the wavemeter. The estimation process involves a (e.g. golden-section) search to determine one or more output values for at least one of the optical parameters, based on an objective function which indicates a difference expected and actual measurements. The expected measurements are generated based on a numerical model incorporating candidate values for the optical parameters.

Provided are a device (4) and a method for online measuring a spectrum for a laser device. The device (4) for online measuring a spectrum for a laser device includes: a first optical path assembly (G1) and a second optical path assembly (G2), and the second optical path assembly (G2) and the first optical path assembly (G1) constitute a measurement optical path. The second optical path assembly (G2) includes: an FP etalon (15) and a grating (18). The homogenized laser beam passes through the FP etalon (15) to generate an interference fringe. The grating (18) is arranged after the FP etalon (15), or is arranged before the FP etalon (15) in the measurement optical path, and is configured to disperse the laser beam passing through the FP etalon (15). A high precision measurement in a wide range for a central wavelength of a laser beam and an accurate measurement for spectral parameters of a corresponding FWHM and E95 are achieved through an arrangement of the FP etalon and the grating “in series” in the measurement optical path. There is no moving element in the measurement optical path, the structure is simple and compact, the measurement precision is high, and the stability is high. The corresponding measurement algorithm is simple and efficient, and has an extremely high scientific research or commercial application value.

The present invention provides a wavelength detection device (10) provided with: a plurality of optical filters (12a, 12b); a splitting unit (11) which splits light and allows the split light to pass through each of the plurality of optical filters (12a, 12b); a plurality of light receiving elements (13a, 13b) which detect the intensities of different beams of light which have passed through the optical filters, respectively; and a calculation unit (16) which calculates, from the outputs of the plurality of light receiving elements, physical quantities related to the transmittances of the plurality of optical filters, and calculates the wavelengths of the beams of light which have passed through the plurality of optical filters, on the basis of the transmittance characteristics, wherein the transmittance characteristics of the plurality of optical filters have an inclination section in different wavelength ranges of the wavelength range of the object to be measured.

A narrow band laser apparatus may include: a laser resonator; a pair of discharge electrodes; a power supply; a first wavelength measurement device configured to output a first measurement result; a second wavelength measurement device configured to output a second measurement result; and a control unit. The control unit calibrates the first measurement result, based on a difference between the second measurement result derived when the control unit controls the power supply to apply a pulsed voltage to the pair of discharge electrodes with a first repetition frequency and the second measurement result derived when the control unit controls the power supply to apply the pulsed voltage to the pair of discharge electrodes with a second repetition frequency, the second repetition frequency being higher than the first repetition frequency.

The invention relates to an optoelectronic chip comprising the following elements: a light inlet; a wavelength-sensitive optical filter; a first photoelectric element for measuring a first light intensity, particularly a first photodiode, the first photoelectric element being arranged such that light penetrating the optoelectronic chip via the light inlet, transmitted by the filter, hits the first photoelectric element; and a second photoelectric element for measuring a second light intensity, particularly a second photodiode, the second photoelectric element being arranged such that the light penetrating the optoelectronic chip via the light inlet, which is reflected by the filter, hits the second photoelectric element.

An optical spectrum analyzer (OSA) for measuring an optical spectrum of an input optical signal in a measurement wavelength range is provided. The OSA comprises a modulator, an integrated optical filter, and a photodetector. The modulator modulates the input optical signal by applying a dither modulation to facilitate detection and noise rejection. The integrated optical filter, which may include a ring resonator system, is sequentially tunable to selectively transmit each wavelength of the modulated optical signal in the measurement wavelength range. The photodetector sequentially detects each wavelength of the modulated optical signal in the measurement wavelength range to provide a representative output electrical signal.

A tunable laser wavelength measurement system includes an interferometric wavelength tracking system that uses a combination of interferometric and wavelength reference measurements to directly measure the laser output wavelength, The measurement exhibits the following desirable error signal characteristics: directional information, continuity, low latency, absolute information, high accuracy, high precision, and little or no drift, A tunable laser wavelength control system additionally incorporates electronics to compare the measured laser wavelength to a desired wavelength or wavelength function, and to generate a feedback control signal to control the wavelength of the laser output based on the comparison. In one non-limiting example implementation, the desired wavelength function is repetitive. The difference between the desired wavelength function and the interferometrically-measured wavelength function is taken, and a successive approximation technique is employed to calculate and adjust a repetitive controlling signal to obtain the desired wavelength function.

A parameter measurement device of a light deflector includes a photodetector that receives output light from the light deflector, a biaxial translation automatic stage that moves the photodetector to a plurality of positions, and a signal processing device that calculates the wavelength of the output light of a wavelength sweeping light source for each time, calculates the wavelength of the light received from the light deflector by the photodetector based on the output signal of the photodetector and a previously-calculated wavelength, and calculates the incident angle of the output light beam of the wavelength sweeping light source onto the diffraction grating and an angle formed by an L-axis and a line perpendicular to the surface of the diffraction grating by performing fitting so that the coordinates of the photodetector that are obtained for each position of the photodetector and the wavelength of the light conform to a prescribed relational expression.

The interferometer 10 according to this disclosure includes: a first optical component 12 that splits each of the P polarization component and the S polarization component of the light to be measured into the first optical path R1 and the second optical path R2 and combines the light to be measured; a second optical component 13 placed in the first optical path; a third optical component 14 that splits the light to be measured into the P polarization component and the S polarization component; and a P polarization detector 11a and an S polarization detector 11b that respectively detect the P polarization component and the S polarization component split by the third optical component, wherein the second optical component has an optical surface that changes the propagation direction of the light to be measured and gives a phase difference between the P polarization component and the S polarization component.