Related Experiment Video
Updated: Jun 19, 2026
08:39
Shaping the Amplitude and Phase of Laser Beams by Using a Phase-only Spatial Light Modulator
Published on: January 28, 2019
Frequency stabilization of a semiconductor laser by external phase-conjugate feedback
Optics Letters
|October 31, 2009
Abstract:
We report the stabilization of a laser diode by external phase-conjugate feedback from a broad-area laser diode. The linewidth of the stabilized laser diode was reduced from 5 MHz to 25 kHz, approaching the limit set by the fluctuations of the pump beam for the phase conjugator. Clear evidence of phase conjugation was the observation of paired half-axial side modes spaced at frequencies of c/4L with respect to the main mode.
Related Concept Videos
01:21Time 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,...
Phase-lag controllers do not place a pole at zero, but instead influence the steady-state error by amplifying any finite,...
01:24Time 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...
The design of phase-lead control involves the strategic placement of poles and zeros to balance steady-state error and system...