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Related Concept Videos

Parallel Resonance01:23

Parallel Resonance

The parallel RLC circuit is an arrangement where the resistor (R), inductor (L), and capacitor (C) are all connected to the same nodes and, as a result, share the same voltage across them. The parallel RLC circuit is analyzed in terms of admittance (Y), which reflects the ease with which current can flow. The admittance is given by:
Time and frequency -Domain Interpretation of Phase-lead Control01:24

Time and frequency -Domain Interpretation of Phase-lead Control

Phase-lead controllers are commonly used in various control systems to enhance response speed and stability. Adjusting the brightness on a television screen offers a practical example of phase-lead control. When contrast is enhanced, a phase-lead controller is employed. Mathematically, phase-lead control is identified when the first parameter is smaller than the second.
The design of phase-lead control involves the strategic placement of poles and zeros to balance steady-state error and system...
Time and frequency -Domain Interpretation of Phase-lag Control01:21

Time and frequency -Domain Interpretation of Phase-lag Control

Phase-lag controllers are widely used in control systems to improve stability and reduce steady-state errors. A dimmer switch controlling the brightness of a light bulb serves as a practical example of phase-lag control, gradually adjusting the bulb's brightness. Mathematically, phase-lag control or low-pass filtering is represented when the factor 'a' is less than 1.
Phase-lag controllers do not place a pole at zero, but instead influence the steady-state error by amplifying any finite,...
Time and frequency -Domain Interpretation of PI Control01:27

Time and frequency -Domain Interpretation of PI Control

Proportional-Integral (PI) controllers are essential in many control systems to improve stability and performance. They are commonly used in everyday devices like thermostats to enhance system damping and reduce steady-state error. When the zero in the controller's transfer function is optimally placed, the system benefits significantly in terms of stability and accuracy.
Acting as a low-pass filter, the PI controller slows the system's response and extends settling times. This requires careful...
Power Factor Correction01:20

Power Factor Correction

The power transmission to a factory involves the transfer of apparent power, a combination of active and reactive power. The power factor measures how effectively electrical power is converted into useful work output. The ratio of the real power (KW) that does the work to the apparent power (KVA) supplied to the circuit.
Frequency-Domain Interpretation of PD Control01:24

Frequency-Domain Interpretation of PD Control

Proportional-Derivative (PD) controllers are widely used in fan control systems to improve stability and performance. A fan control system can be effectively represented using a Bode plot to illustrate the impact of a PD controller through its transfer function. The Bode plot visually conveys how PD control modifies the fan's response across various frequencies, providing a frequency domain interpretation of the controller's behavior.
The proportional control gain, combined with the system's...

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Related Experiment Video

Updated: Jun 15, 2026

Generation and Coherent Control of Pulsed Quantum Frequency Combs
06:42

Generation and Coherent Control of Pulsed Quantum Frequency Combs

Published on: June 8, 2018

Frequency-modulated zone plate for coherent noise reduction.

P C Mehta, R Hradaynath

    Applied Optics
    |March 10, 2010
    PubMed
    Summary

    A novel phase plate effectively reduces speckle noise in laser imaging and holographic reconstructions. This frequency-modulated zone plate offers a simpler, lens-free solution for clearer optical images.

    Area of Science:

    • Optics and Photonics
    • Image Processing
    • Holography

    Background:

    • Laser imaging and holographic reconstructions are susceptible to speckle noise from optical component imperfections.
    • This noise manifests as undesirable noiselike structures in the final reconstructed images, degrading quality.

    Purpose of the Study:

    • To propose and demonstrate a novel phase plate for reducing speckle noise in optical imaging systems.
    • To introduce a frequency-modulated zone plate that simplifies system design by eliminating the need for a separate Fourier transforming lens.

    Main Methods:

    • Fabrication of a phase plate using holographic techniques.
    • Integration of the phase plate into an optical imaging system to mitigate speckle noise.
    • Experimental validation of the phase plate's performance.

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    Last Updated: Jun 15, 2026

    Generation and Coherent Control of Pulsed Quantum Frequency Combs
    06:42

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    Published on: June 8, 2018

    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

    Main Results:

    • The proposed phase plate effectively reduces speckle noise in laser images and holographic reconstructions.
    • Experimental results confirm the capability of the frequency-modulated zone plate in noise suppression.
    • The system demonstrated improved image quality without requiring an additional Fourier transforming lens.

    Conclusions:

    • The frequency-modulated zone plate is a viable and effective solution for speckle noise reduction in optical imaging.
    • Holographic fabrication offers a practical method for creating these specialized phase plates.
    • The proposed approach simplifies optical system design and enhances image fidelity.