The application discloses a light scattering parameter measurement system and its measurement method. Dual-frequency scattering interference technology is adopted to obtain distributed measurement of Rayleigh scattering parameters in an optical fiber. The Rayleigh scattering coefficient r and phase retardance θ are modulated on different components of the interference signal respectively by using the dual-frequency interference technology. The Rayleigh scattering coefficient r and phase retardance θ can be decoupled by simple filtering, to obtain separate measurements. A linear stretch is applied to the optical fiber under test, to add uniform phase change signals at all positions of the optical fiber under test. As a result, the term containing only Rayleigh scattering coefficient r can be extracted by low-pass filtering. The direct measurement of Rayleigh scattering parameters is of great significance to fundamental and application researches related to Rayleigh scattering of optical fiber.

A testing device includes a test port, a light source, a measurement element, and a controller. A method of testing an optical system with the testing device includes, and/or the testing device is configured for, measuring an unloaded reference signal when the testing device is not connected to the optical system and storing the unloaded reference signal in a memory of the testing device. The method and/or configuration also includes detecting a signal from the optical system after storing the unloaded reference signal. Based on the detected signal, it is determined that the optical system is connected to a test port of the testing device. A test of the optical system with the testing device is automatically initiated in response to determining that the optical system is connected to the test port of the testing device.

The present disclosure relates to an inspection apparatus and an inspection method that enable inspection of the performance of an image pickup element. Generation of collimated light and transmission of part of the collimated light through a transmission filter having a light-blocking face provided with circular holes arranged regularly, causes conversion to rays of columnar collimated light arranged regularly. An image including the rays of columnar collimated light arranged regularly, is captured by an image pickup element being inspected. Then, acquisition of the difference between the image captured by the image pickup element being inspected and an ideal image captured by an ideal image pickup element and comparison between the difference and a threshold, result in inspection of the performance of the image pickup element being inspected.

A wafer-grade LED detection device and a wafer-grade LED detection method are provided. The wafer-grade LED detection device includes a light-generating module for providing a first light beam that passes through an LED wafer to be converted into a second light beam, a light-filtering module adjacent to the LED wafer for receiving the second light beam that passes through the light-filtering module to be converted into a third light beam, and a light-detecting module adjacent to the light-filtering module for receiving and detecting the third light beam. A wavelength range of the second light beam is restricted by the light-filtering module, so that a wavelength range of the third light beam is smaller than the wavelength range of the second light beam. When the third light beam is received by the light-detecting module, the light-detecting module can detect the third light beam for obtaining relevant information.

A system for producing a high contrast image of an ophthalmic lens under inspection, comprising: top camera to view ophthalmic lens through lens module; motorized mechanism for positioning top camera at two pre-programmed positions; three illumination modules; said illumination modules focusing light through ophthalmic lens under inspection, thereby producing a high contrast image of features of ophthalmic lens; wherein ophthalmic lens is contained within cuvette with optical power of positive of ten; said cuvette mounted with two optical windows, one of them being vertical and other at an angle; said cuvette having transparent bottom glass suitably designed to position ophthalmic lens under inspection; said cuvette designed to be filled with saline solution; accurately calibrated test object positioned to achieve image of ophthalmic lens overlaid with image of pattern present on test object; additional illumination source comprising laser diode; and second camera to view ophthalmic lens through slanted optical lens module.

A lensmeter capable of measuring near-infrared ray transmittance of an eyeglass lens by adding a near-infrared ray measurement function to the lensmeter. The lensmeter includes a near-infrared ray transmittance measuring unit that includes a light emitting unit including a near-infrared ray light source for irradiating a measured lens with a near-infrared ray; and a light receiving unit including a near-infrared ray sensor for measuring a near-infrared ray transmittance of the measured lens by detecting an intensity of the near-infrared ray passing through the measured lens, and is located at one end of a housing of the lensmeter.

The present invention relates to a device for measuring an optical element comprising: a. a light source, b. a measurement structure which illuminated by the light of the light source and has areas of different transmissivity, c. an optical imaging system for converting light transmitted by the measurement structure into a collimated measuring beam which is directed onto the optical element, and d. a sensor for detecting a reflection of the measuring beam generated on the optical element for detecting a transmission of the measuring beam passing through the optical element. According to the invention the light source has a plurality of light segments, wherein the device further comprises a control unit which is designed for independently controlling the plurality of light segments. The invention further relates to a corresponding method for measuring an optical element. The device according to the invention and the method according to the invention can be used particularly flexibly due to the segmented light source.

An object of the present disclosure is to provide a few-mode fiber testing method and a few-mode fiber testing device capable of acquiring a loss and inter-mode crosstalk for each mode at a connection point of a few-mode fiber by measurement only from one end of FUT. The few-mode fiber testing method according to the present disclosure includes receiving a test light pulse in a basic mode from one end of an optical fiber under test that is connected in series with few-mode fibers of the same type, measuring an intensity distribution relating to a distance from the one end of backward Brillouin scattering light generated by receiving a test light pulse, obtaining a transmittance of the backward Brillouin scattering light at a connection point of the optical fiber under test from the measured intensity distribution, and calculating a connection loss of the basic mode from the transmittance, calculating a ratio of an axial deviation amount to a mode field radius of the optical fiber under test at the connection point from the calculated connection loss, and calculating a connection loss of a higher-order mode and inter-mode crosstalk between different modes from the calculated ratio.

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.

An optical path test system includes a return light test unit for emitting laser light to an optical path monitoring unit to simulate return light received by the optical path monitoring unit in a normal operation; a light path monitoring unit arranged on a light path of the return light testing unit for receiving the return light and normally emitting laser light; and a power detector for receiving the laser light emitted by the light path monitoring unit so as to monitor stability of output power of the chip when the light path monitoring unit receives the return light emitted by the return light testing unit. The technical solution in the present invention emits laser light to a tested laser chip to simulate return light received by the tested laser chip in a normal operation, and a return light resistance threshold of the laser chip can be accurately evaluated.