Related Experiment Video
Updated: Oct 29, 2025

10:53
Simultaneous Measurement of Turbulence and Particle Kinematics Using Flow Imaging Techniques
Published on: March 12, 2019
7.2K
Time-lens photon Doppler velocimetry (TL-PDV)
Pinghan Chu1, Velat Kilic2, Mark A Foster2
1Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
The Review of Scientific Instruments
|July 10, 2021
Summary
A novel time lens (TL) enhances photon Doppler velocimetry (PDV) systems by expanding dynamic range. This technology, demonstrated through simulations, allows for broader velocity measurements and use of lower bandwidth electronics.
Area of Science:
- Photonics and Optical Engineering
- Advanced Measurement Techniques
Background:
- Photon Doppler velocimetry (PDV) measures target motion via Doppler frequency shifts.
- Current PDV systems face limitations in velocity range due to electronic sampling rates.
Purpose of the Study:
- To introduce a time lens (TL) system for expanding the dynamic range of PDV.
- To demonstrate the feasibility of TL-PDV for enhanced velocity measurements.
Main Methods:
- Utilizing a four-wave-mixing (FWM) time lens to apply quadratic temporal phase modulation to optical signals.
- Employing nonlinear media like integrated photonic waveguides or highly nonlinear optical fibers.
- Implementing spectral isolation of the FWM idler product and dispersion management for temporal magnification.
Main Results:
- Simulations confirm the feasibility of the TL-PDV principle.
- A magnification factor (M) of 10 is shown to be achievable for the time lens.
- The system effectively "slows down" Doppler frequency shifts.
Conclusions:
- The developed TL-PDV system significantly expands the velocity measurement range of PDV.
- This advancement enables the use of lower bandwidth electronics, reducing system complexity and cost.
- TL-PDV is poised to facilitate new research in dynamic material experiments.
Related Concept Videos
Doppler Effect - II
3.8K
The Doppler effect has several practical, real-world applications. For instance, meteorologists use Doppler radars to interpret weather events based on the Doppler effect. Typically, a transmitter emits radio waves at a specific frequency toward the sky from a weather station. The radio waves bounce off the clouds and precipitation and travel back to the weather station. The radio frequency of the waves reflected back to the station appears to decrease if the clouds or precipitation are moving...
3.8K
Doppler Effect - I
4.0K
The Doppler effect and Doppler shift were named after the Austrian physicist and mathematician Christian Johann Doppler in 1842, who conducted experiments with both moving sources and moving observers. Consider an observer standing on a street corner, observing an ambulance with a siren sound passing by at a constant speed. The observer experiences two characteristic changes in the sound of the siren. Initially, the sound increases in loudness as the ambulance approaches and decreases in...
4.0K
Relative Motion Analysis - Velocity
501
A stroke engine has a slider-crank mechanism that converts rotational motion from the crank into linear motion of the slider or vice versa. This mechanism consists of three main parts: the crank, the connecting rod, and the slider.
When an external force is exerted, it sets the crank into a rotational movement. This, in turn, instigates the motion of the connecting rod, leading to what is referred to as a general plane motion. This process involves two key points - point A on the connecting rod...
When an external force is exerted, it sets the crank into a rotational movement. This, in turn, instigates the motion of the connecting rod, leading to what is referred to as a general plane motion. This process involves two key points - point A on the connecting rod...
501

