相关实验视频

Updated: Jan 8, 2026

Transmission of Multiple Signals through an Optical Fiber Using Wavefront Shaping
09:43

Transmission of Multiple Signals through an Optical Fiber Using Wavefront Shaping

Published on: March 20, 2017

10.3K

基于局部星座分解联合塑造的超高阶QAM调制方法

Ying Zhang, Jiaqi Wang, Wenxiang Yao

    Optics express
    |December 19, 2025
    PubMed
    概括

    这项研究引入了超高阶方格振幅调制 (QAM) 信号的新型联合塑造方案,改善了使用德尔塔-西格玛调制 (DSM) 的强度调制直接检测 (IMDD) 系统中的比特误差率 (BER) 性能. 该方法提高了接收器的灵敏度和系统效率.

    更多相关视频

    Shaping the Amplitude and Phase of Laser Beams by Using a Phase-only Spatial Light Modulator08:39

    Shaping the Amplitude and Phase of Laser Beams by Using a Phase-only Spatial Light Modulator

    Published on: January 28, 2019

    10.3K
    Quasi-light Storage for Optical Data Packets07:45

    Quasi-light Storage for Optical Data Packets

    Published on: February 6, 2014

    11.3K

    相关概念视频

    ¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)01:20

    ¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)

    When proton-coupled carbon-13 spectra are simplified by a broadband proton decoupling technique, structural information about the coupled protons is lost. Distortionless enhancement by polarization transfer (DEPT) is a technique that provides information on the number of hydrogens attached to each carbon in a molecule. While the DEPT experiment utilizes complex pulse sequences, the pulse delay and flip angle are specifically manipulated. The resulting signals have different phases depending on...
    1.6K
    Linear Approximation in Frequency Domain01:26

    Linear Approximation in Frequency Domain

    Linear systems are characterized by two main properties: superposition and homogeneity. Superposition allows the response to multiple inputs to be the sum of the responses to each individual input. Homogeneity ensures that scaling an input by a scalar results in the response being scaled by the same scalar.
    In contrast, nonlinear systems do not inherently possess these properties. However, for small deviations around an operating point, a nonlinear system can often be approximated as linear....
    329
    IR Spectrum Peak Splitting: Symmetric vs Asymmetric Vibrations01:08

    IR Spectrum Peak Splitting: Symmetric vs Asymmetric Vibrations

    Identical bonds within a polyatomic group can stretch symmetrically (in-phase) or asymmetrically (out-of-phase). Similar to hydrogen bonding, these vibrations also influence the shape of the IR peak. Generally, asymmetric stretching frequencies are higher than symmetric stretching frequencies. For example, primary amines exhibit two distinct IR peaks between 3300–3500 cm−1 corresponding to the symmetric and asymmetric N-H stretching, while secondary amines exhibit a single...
    1.7K
    Upsampling01:22

    Upsampling

    Managing signal sampling rates is essential in digital signal processing to maintain signal integrity. A decimated signal, characterized by a reduced frequency range due to its lower sampling rate, can be upsampled by inserting zeros between each sample. This upsampling process expands the original spectrum and introduces repeated spectral replicas at intervals dictated by the new Nyquist frequency. To refine this zero-inserted sequence, it is passed through a lowpass filter with a cutoff...
    568
    Area Computation by the Alternative Coordinate Method01:24

    Area Computation by the Alternative Coordinate Method

    The alternative coordinate method, also known as the Shoelace Formula, is a technique for determining the area of a traverse using Cartesian coordinates. This method relies on the sequential arrangement of x and y coordinates for each point of the shape, ensuring accuracy and ease of application.In this approach, each corner's x and y coordinates are listed as fractions, with the x-coordinate as the numerator and the y-coordinate as the denominator. These coordinates are arranged sequentially...
    528
    IR Spectrum Peak Intensity: Dipole Moment01:20

    IR Spectrum Peak Intensity: Dipole Moment

    The dipole moment of a bond is the product of the partial charge on either atom and the distance between them. Dipole moments influence the efficiency of IR absorption and the peak intensity. When a bond with a dipole moment is placed in an electric field, the direction of the field determines if the bond is compressed or stretched. Electromagnetic radiation consists of an electric field component that rapidly reverses direction. It follows that polar bonds are alternately stretched and...
    1.4K