Related Experiment Video
Updated: Jan 7, 2026
16:11
Implementation of a Reference Interferometer for Nanodetection
Published on: April 26, 2014
9.7K
Ranging beyond synthetic wavelengths with an undersampled spectral signal using tunable wavelength laser
Optics Letters
|December 24, 2025
Summary
This study demonstrates precise centimeter-scale ranging and micrometer-level profile resolution by extending measurement range beyond synthetic wavelength limits using continuous wavelength tuning and tilted interference. This method enables unique extended range measurements and sample profiling.
Area of Science:
- Optical Metrology
- Interferometry
- Signal Processing
Background:
- Accurate ranging and surface profiling are crucial in various scientific and industrial applications.
- Traditional methods face limitations in range and resolution, particularly with spectrally undersampled signals.
Purpose of the Study:
- To develop a novel method for extending measurement range beyond the synthetic wavelength limit.
- To achieve precise centimeter-scale ranging and micrometer-level profile resolution.
- To enable unique extended range measurements and sample profiling from a single wavelength scan.
Main Methods:
- Continuous tuning of the source wavelength.
- Utilizing tilted interference for excess fraction extraction from spectrally undersampled signals.
- Employing a cascaded Michelson interferometer and Fourier transform method for fringe analysis.
Main Results:
- Achieved range extension beyond the longest synthetic wavelength.
- Demonstrated unique measurement of the extended range and spatial sample profile.
- Obtained centimeter-scale ranging with sub-nanometer wavelength tuning resolution.
- Achieved micrometer-level profile resolution.
Conclusions:
- Continuous wavelength tuning combined with tilted interference enables precise extended range measurements.
- The cascaded Michelson interferometer offers a robust platform for simultaneous ranging and profiling.
- This technique significantly enhances capabilities in optical metrology for high-precision applications.
Related Concept Videos
01:18Aliasing
520
Accurate signal sampling and reconstruction are crucial in various signal-processing applications. A time-domain signal's spectrum can be revealed using its Fourier transform. When this signal is sampled at a specific frequency, it results in multiple scaled replicas of the original spectrum in the frequency domain. The spacing of these replicas is determined by the sampling frequency.
If the sampling frequency is below the Nyquist rate, these replicas overlap, preventing the original...
If the sampling frequency is below the Nyquist rate, these replicas overlap, preventing the original...
520
01:25IR Spectrometers
2.2K
There are two main infrared (IR) spectrophotometers: dispersive IR spectrometers and Fourier transform infrared (FTIR) spectrometers. In a dispersive IR spectrometer, a beam of infrared radiation produced by a hot wire is divided into two parallel equal-intensity beams using mirrors. One beam passes through the sample, while another is a reference beam. The beams then move through the monochromator, which separates the radiations into a continuous spectrum of different frequencies. The...
2.2K
01:22Upsampling
565
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...
565
01:10Reconstruction of Signal using Interpolation
660
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...
660