48results about How to "Wide working band" patented technology

The invention provides an ultra-wideband perfect absorber in the mid-infrared band and a preparation method thereof. The absorber is sequentially provided with a base layer, a non-metallic dielectric layer, a metal absorption layer and a non-metallic anti-reflection layer from bottom to top. The metal dielectric layer is connected to the upper surface of the base layer. The metal absorption layer is composed of a plurality of metal absorption units, and the absorber has the advantages of high absorption efficiency, insensitivity to angle, wide operating band and good thermal stability, and surpasses the traditional absorber in performance.

The invention relates to an optical signal modulation format recognition method and system based on nonlinear digital processing in the field of optical fiber communications. The system comprises a TDC, an OA, an optical filter, a high-speed optical detector, a low-speed asynchronous sampler, an analog-digital converter and a main control module. The main control module drives the TDC to generate a series of chromatic dispersion values, N sampling digital signals p1, p2, ... and pN are recorded under each chromatic dispersion value, and an output signal <Pout> is calculated according to the formula that <Pout>=1 / N *Sigma Nj=1(kpj)<n>, wherein n is the order and k is the adjusting coefficient; the <Pout> values obtained under the chromatic dispersion values are stored to be feature value arrays in order of the chromatic dispersion values, the feature value arrays are matched with feature value array samples of signals of the known modulation format, and therefore the modulation formats of input optical signals are judged. The method and system are applicable to signals of various modulation formats and rates, the working waveband is wide, greater tolerance is achieved for signal transmission chromatic dispersion and OSNR degradation, and the requirement for the rates of sampling and the analog-digital converter is low. The method and system have the advantages of being simple in structure, high in cost performance and wide in application range.

The invention relates to a polarization multiplexing and non-polarization multiplexing optical signal identification method and system in the field of optical fiber communication. The system includes an optical filter, a dispersion module, a high-speed photodetector, a sampler, an analog-to-digital converter and a digital signal processing module. The identification method includes the steps of: extracting the channel to be identified, applying a set dispersion to the signal to be identified, obtaining the time-domain digital sampling value of the signal, performing normalization processing, calculating the power distribution histogram of the output signal, and finding the maximum value of the histogram For the corresponding abscissa, the polarization multiplexed signal and the non-polarization multiplexed optical signal are identified according to the relative size of the maximum abscissa and the decision threshold. The present invention is applicable to signals of various rates and modulation formats, has a wide operating band, and has a large tolerance for signal quality degradation caused by optical fiber dispersion, polarization mode dispersion and amplifier noise in signal transmission, and has simple structure, high cost performance, and wide application range Wide and easy to use advantages.

The medium-short and wide-band infrared optical system and remote sensing optical equipment provided by the present invention adopt the configuration of a straight cylindrical primary imaging system. The optical system is composed of four spherical mirrors, and all components are arranged on the same optical axis. It has a wide working band, compact structure, Good fit, good imaging quality, transfer function at or close to the diffraction limit, etc.

The invention relates to a modulation format identification method and system based on signal spectral characteristics. The system comprises an optical amplifier (OA), an optical spectrum apparatus (OSA) and a data signal processing (DSP) system. First, an optical signal to be identified enters the OA and is amplified to have certain power, then injected to the OSA; center frequency estimation of the optical spectrum output from the OSA is carried out; using the center frequency as a reference, optical signal spectrums having a frequency range of + / -100GHz are intercepted; a characteristic vector of the optical sample is abstracted through a principal component analysis (PCA) algorithm module; the characteristic vector is input in an algorithm identification module of a pre-trained support vector machine (SVM) to determine the modulation formats and speed of the optical signal under test. The provided method requires no prior information to work and is suitable for switch modulation and advanced modulation format signals; no high speed detector is required; the method has large signal transmission damage tolerance, simple structure and wide application range.

The invention discloses an optically controlled optical switch, which comprises a magnetic base, a graphene sheet with a gap and a driving light source, the graphene sheet is suspended on the magnetic base under the action of a magnetic field, and the graphene sheet is provided with a A driving light source for driving the circular motion of the graphene sheet. The beneficial effect of the present invention is: by controlling light irradiation, changing the magnetic polarization direction deflection of the graphene sheet, thereby rotating under the action of the magnetic field, so that the regulated light passes through or does not pass through the gap, so as to realize the modulation of the regulated light. The light-controlled optical switch can realize simultaneous modulation in the range of ultraviolet to infrared spectrum, and the modulation speed is fast and the modulation efficiency is high.