Acousto-optic frequency shifted comb laser-based micro-Doppler detection for moving target identification

Area of Science:

• Optics and Photonics
• Laser Technology
• Sensing Systems

Background:

• Micro-Doppler detection is crucial for identifying moving objects, but existing systems face challenges with stability and size.
• Acousto-optic frequency shifting (AOFS) offers a method to generate complex laser outputs.

Purpose of the Study:

• To experimentally demonstrate a novel micro-Doppler detection system utilizing an acousto-optic frequency shifted (AOFS) comb laser.
• To assess the system's capability for identifying moving objects with both linear and rotational motion.

Main Methods:

• Constructed an AOFS comb laser by frequency shifting a seed laser at 1063.8 nm using an acousto-optic modulator in an amplified fiber loop.
• Generated stable pulsed output (150 MHz repetition rate, 200 ps duration) from the AOFS comb laser.
• Utilized heterodyne detection of the pulse echo comb laser and a continuous-wave local laser to derive micro-Doppler signals from a moving object.

Main Results:

• Successfully demonstrated a preliminary experimental setup for micro-Doppler detection.
• The system generated a stable pulsed output suitable for sensing applications.
• Micro-Doppler signals corresponding to object rotation were successfully derived.

Conclusions:

• The developed AOFS comb laser-based system shows significant potential for micro-Doppler detection.
• The system's long-term stability and compactness make it suitable for high-speed target identification.
• This technology offers a promising advancement in moving object sensing capabilities.