Related Experiment Video
Updated: Jun 23, 2026
08:39
Shaping the Amplitude and Phase of Laser Beams by Using a Phase-only Spatial Light Modulator
Published on: January 28, 2019
Easy and straightforward construction of wideband phase-shifting algorithms for interferometry
J C Estrada1, M Servin, J A Quiroga
1Centro de Investigaciones en Optica Asociacion Civil, León Guanajuato 20036, México. jcesar_estrada@hotmail.com
Optics Letters
|April 18, 2009
Summary
This study introduces a practical method for creating wideband phase-shifting algorithms in interferometry by combining quadrature filters. This approach enhances detuning robustness and bandwidth for improved interferometric measurements.
Area of Science:
- Optical Engineering
- Signal Processing
- Interferometry
Background:
- Phase-shifting algorithms are crucial for interferometry but often limited in bandwidth and robustness to detuning.
- Existing methods may require complex calibration or are sensitive to environmental changes.
Purpose of the Study:
- To present a practical and systematic method for developing wideband phase-shifting algorithms for interferometry.
- To enhance the robustness of phase-shifting algorithms against frequency detuning.
- To provide a powerful tool for frequency analysis and design in interferometric applications.
Main Methods:
- Combining first- and second-order quadrature filters as fundamental building blocks.
- Developing a systematic approach analogous to filter design in communications engineering.
- Analyzing the frequency response and detuning robustness of the proposed algorithms.
Main Results:
- Demonstration of a practical method for constructing wideband phase-shifting algorithms.
- Achieved algorithms exhibit significant robustness to detuning.
- The approach provides a systematic design tool for interferometric phase analysis.
Conclusions:
- The proposed method offers a powerful and systematic way to design wideband phase-shifting algorithms for interferometry.
- The developed algorithms are robust to detuning, improving measurement reliability.
- This work provides a valuable frequency analysis and design tool for optical metrology.
Related Concept Videos
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...
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,...
01:10Reconstruction of Signal using Interpolation
Signal processing techniques are essential for accurately converting continuous signals to digital formats and vice versa. When a continuous signal is sampled with a period T, the resulting sampled signal exhibits replicas of the original spectrum in the frequency domain, spaced at intervals equal to the sampling frequency. To handle this sampled signal, a zero-order hold method can be applied, which creates a piecewise constant signal by retaining each sample's value until the next sampling...
01:10Interference: Path Lengths
Consider two sources of sound, that may or may not be in phase, emitting waves at a single frequency, and consider the frequencies to be the same.
Two special sources may be considered when they are in phase. This can be easily achieved by feeding the two sources from the same source. An example would be synchronizing the two speakers by feeding them with the same source, such as the sound waves produced by a tuning fork. This setup ensures that the two sources have the same frequency and are...
Two special sources may be considered when they are in phase. This can be easily achieved by feeding the two sources from the same source. An example would be synchronizing the two speakers by feeding them with the same source, such as the sound waves produced by a tuning fork. This setup ensures that the two sources have the same frequency and are...
02:18Interference and Diffraction
Interference is a characteristic phenomenon exhibited by waves. When two electromagnetic waves interact with their peaks and troughs coinciding, a resulting wave with enhanced amplitude is produced. This is known as constructive interference. In this case, the two waves interacting are in phase with each other.
01:22Phase-lead and Phase-lag Controllers
Understanding the working function of different types of controllers can be illustrated with practical analogies, such as adjusting a stereo's volume equalizer. Cranking up the bass involves a phase-lead controller, which functions as a high-pass filter, while increasing the treble uses a phase-lag controller, which acts as a low-pass filter. PD controllers, similar to high-pass filters, enhance the system's response to high-frequency components. PI controllers, akin to low-pass filters, manage...