We propose a laser heterodyne digital holography microscopy system based on a moving grating, which uses the Doppler principle between a moving grating and beam to achieve a low-frequency bias between the diffracted beams, abandoning traditional heterodyne digital holography that requires multiple acousto-optic modulators. The dynamic phase distribution obtained using the laser heterodyne digital holography phase-reconstruction algorithm was more realistic and analyzable than the results of the angular spectrum algorithm. The structure and algorithm were used to capture the shape characteristics of mouse fibroblasts after ~2 h of incubation (37°C, 5% CO), and the dynamic phase distribution of the cells was monitored in real-time during the attachment process. The system proposed in this study, with its high spatial resolution and high-precision phase measurement capability, is suitable for both static and live cells.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1002/jbio.202300355 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
A heterodyne laser Doppler vibrometer (LDV) with a Bragg cell has a stationary signal carrier at a frequency of at least 35 MHz. The expensive Bragg cell with the restricted shift frequency is not an optimal solution to meet the requirements for many measurement scenarios. For vibrations with low frequencies and small amplitudes, a tens-of-megahertz carrier frequency not only wastes bandwidth at the photodetector but also requires a fast and expensive analog-to-digital converter (ADC).
View Article and Find Full Text PDFArticle Synopsis
- Laser frequency noise is problematic in low-frequency measurements, but can be mitigated using differential measurement schemes with heterodyne optical phase-locked loops.
- The study demonstrates simultaneous optical phase-locked loops with notable specifications, achieving a 300 MHz offset range and an impressive 250 dB open-loop gain at 0.1 Hz.
- A four-laser differential measurement setup is detailed, effectively suppressing relative free-running noise to enhance measurement precision below 0.1 / at 0.1 Hz.
Article Synopsis
- This paper examines how well a 100 Gb/s coherent passive optical network (PON) can handle laser phase noise using distributed feedback (DFB) lasers as local oscillators.
- The study employs digitally subcarrier-multiplexed (DSCM) signals generated with Alamouti encoding, showing strong performance with power budgets of 34.2 dB and 33.9 dB over a 25 km fiber link, depending on the type of laser used.
- Advanced digital signal processing techniques are utilized for phase noise compensation and frequency offset estimation, highlighting the importance of low-pass filter settings and pre-equalization for optimal system performance.
Spatial heterodyne one-dimensional imaging spectrometer (SHIS) can simultaneously acquire hyperspectral information from different fields of view (FOVs). However, the dynamic range of SHIS is limited by the detector's performance. We propose a high dynamic range spatial heterodyne one-dimensional imaging spectroscopy (HD-SHIS) based on a digital micromirror device (DMD), which can control the exposure time of each FOV signal by adjusting the flip time of micromirrors on an M-bit DMD, realizing the simultaneous detection of strong and weak signals in FOVs with a theoretical improvement of the dynamic range by dB.
View Article and Find Full Text PDFTime and frequency division multiplexing (TFDM) coherent passive optical networks (PONs) are considered as a promising candidate for future optical access networks due to the advantage of high sensitivity, high spectral efficiency, and flexibility. We propose a novel, to our knowledge, bidirectional TFDM 200-Gb/s coherent PON architecture based on the digital subcarrier multiplexing (DSCM) technology. A polarization-insensitive simplified coherent receiver is achieved at the ONU side by Alamouti coding and heterodyne detection.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!