An electronic device with an auxiliary lighting function and an operation method thereof are provided. The electronic device includes a first body, a display screen, and a light-emitting module. The first body has a first surface. The first surface includes a screen area and a border area. The border area surrounds the screen area. The display screen is disposed in the screen area of the first body. The light-emitting module is disposed in the border area of the first body. The light-emitting module provides an illumination light in at least one first area of the border area, and provides an indicating light in at least one second area of the border area.

A photodetector device includes an avalanche photodiode array substrate. A circuit substrate includes time measurement circuits and a clock driver. Each of the time measurement circuit includes a delay line unit, and is arranged to acquire, from an operation result of a delay line, time information indicating timing at which a pulse signal is input from a corresponding avalanche photodiode. The delay line unit is arranged to initiate an operation of the delay line in response to input of the pulse signal to the time measurement circuit, and to stop the operation of the delay line in response to input of a clock signal from a clock driver to the time measurement circuit, and is arranged to detect a time interval shorter than a cycle of the clock signal by the operation of the delay line.

Methods and devices are described for performing an all-phase measurement of an ultra-fast laser pulse having a spectral range of greater than one octave. The ultra-fast laser pulse may be split into a first beam comprising a fundamental light with a wavelength λ.sub.0 and a second beam comprising a light with a wavelength 2λ.sub.0. The light with the wavelength 2λ.sub.0 may be frequency doubled to a light with a wavelength λ.sub.0 to generate an interference with the fundamental light. Fourier transform may be performed on an interference spectrum of the interference, and a relative envelope delay (RED) between the fundamental light and the frequency doubled light and a carrier envelope phase (CEP) may be acquired based on a result of the Fourier transform.

A method and a system for generating a time-frequency representation of an aperiodic continuous input signal comprising generating a periodic train of short pulses having a repetition frequency, and sampling the signal temporally using the periodic train of short pulses to obtain a temporally sampled signal, the temporally sampled signal comprising a plurality of sampled copies of the input signal, each sampled copy being spaced in function of the repetition frequency of the periodic train of short pulses. The temporally sampled signal is delayed based on the repetition frequency to obtain a delayed temporally sampled signal comprising a plurality of delayed sampled copies, a spectral representation of a given delayed sampled copy being delayed in function of the repetition frequency. The delayed temporally sampled signal is evaluated over consecutive time slots to obtain, for each consecutive time slot, a respective output signal in the time-frequency domain.

A method and a system for generating a time-frequency representation of an aperiodic continuous input signal comprising generating a periodic train of short pulses having a repetition frequency, and sampling the signal temporally using the periodic train of short pulses to obtain a temporally sampled signal, the temporally sampled signal comprising a plurality of sampled copies of the input signal, each sampled copy being spaced in function of the repetition frequency of the periodic train of short pulses. The temporally sampled signal is delayed based on the repetition frequency to obtain a delayed temporally sampled signal comprising a plurality of delayed sampled copies, a spectral representation of a given delayed sampled copy being delayed in function of the repetition frequency. The delayed temporally sampled signal is evaluated over consecutive time slots to obtain, for each consecutive time slot, a respective output signal in the time-frequency domain.

A device, a system and a method for homodyne solid-state biased coherent detection of terahertz pulses in a range between 0.1 and 11 THz, the device comprising a metallic slit between, and parallel to, two longitudinal metallic electrodes, deposited on a surface of a substrate, and covered with a layer of nonlinear material, wherein a width of the metallic slit and a thickness of the nonlinear material layer are selected in relation to a central wavelength of the THz pulses. The method comprises focusing a THz beam and a pulsed laser beam of pulse energies in a range between 10 and 100 nJ onto the metallic slit, the metallic electrodes being biased by a static DC voltage bias selected in a range between 20 V.sub.PP and 200 V.sub.PP; and retrieving a terahertz pulse waveform using the terahertz pulse repetition rate as synchronism.

A device, a system and a method for homodyne solid-state biased coherent detection of terahertz pulses in a range between 0.1 and 11 THz, the device comprising a metallic slit between, and parallel to, two longitudinal metallic electrodes, deposited on a surface of a substrate, and covered with a layer of nonlinear material, wherein a width of the metallic slit and a thickness of the nonlinear material layer are selected in relation to a central wavelength of the THz pulses. The method comprises focusing a THz beam and a pulsed laser beam of pulse energies in a range between 10 and 100 nJ onto the metallic slit, the metallic electrodes being biased by a static DC voltage bias selected in a range between 20 V.sub.PP and 200 V.sub.PP; and retrieving a terahertz pulse waveform using the terahertz pulse repetition rate as synchronism.

A pulse analysis system or method includes a frequency filter that receives an ultrafast pulse under test and disperses the pulse under test over a frequency range. The frequency filter separates the pulse under test into component frequency slices and provides the frequency slices to a detector coupled to a digitizer, which processes the digitized signal and collects a sonogram characteristic of the pulse under test. The frequency slices are arranged to overlap. Ptychography is performed on the sonogram to obtain characteristics of the pulse under test.

Super continuum light having a continuous spectrum over at least 1100 to 1300 nm is emitted from a pulsed light source, is pulse-stretched by a stretching element such that a relationship between a wavelength and an elapsed time in one pulse is one to one, and is radiated to a product. The light transmitted through the product is received by a light receiver, and output data is input to the determination unit. A quality determination program of the determination unit calculates an absorption spectrum from the output data, quantifies the absorption spectrum by chemometrics, and compares the absorption spectrum with a reference value to determine quality. The product determined to be a defective product is excluded by an exclusion mechanism.

A dispersion measurement apparatus includes a pulse forming unit, a correlation optical system, a photodetection unit, and an operation unit. The pulse forming unit forms a light pulse train including a plurality of light pulses having time differences and center wavelengths different from each other from a measurement target light pulse output from a pulsed laser light source. The correlation optical system receives the light pulse train output from the pulse forming unit and outputs correlation light including a cross-correlation or an autocorrelation of the light pulse train. The photodetection unit detects a temporal waveform of the correlation light output from the correlation optical system. The operation unit estimates a wavelength dispersion amount of the pulsed laser light source based on a feature value of the temporal waveform of the correlation light.