Cost-effective time-stretch terahertz recorders, using 1550 nm probes

Area of Science:

• Terahertz (THz) spectroscopy
• Electro-optic detection
• Photonics and optical engineering

Background:

• Time-stretch electro-optic detection enables high-speed, single-shot THz waveform recording, crucial for accelerator physics and THz time-domain spectroscopy.
• High costs associated with fast analog-to-digital converters (ADCs) and oscilloscopes have limited the widespread adoption of this technique.
• Increased sample requirements per waveform further escalate the cost, hindering broader application.

Purpose of the Study:

• To develop a cost-effective THz time-stretch recorder.
• To decrease the required oscilloscope bandwidth and/or increase recorded samples within a budget.
• To leverage the high dispersion of 1550 nm fiber optic probes for improved performance.

Main Methods:

• Utilized 1550 nm probe lasers and standard telecommunication dispersion compensation fibers.
• Designed an experimental setup using commercially available, standard optical components.
• Tested the system with 100 ps THz pulses (≈0.75 THz bandwidth) from the SOLEIL synchrotron facility.

Main Results:

• Achieved a significant reduction in cost by using lower-bandwidth oscilloscopes (1-3 GHz).
• Recorded THz waveforms with an unprecedented time-bandwidth product of ≈100 over a ≈130 ps window.
• Demonstrated high sensitivity, detecting birefringence in the crystal down to 0.5 mrad.

Conclusions:

• The developed THz time-stretch recorder offers a cost-effective solution for high-fidelity THz waveform acquisition.
• This approach enhances the feasibility of table-top THz time-domain spectroscopy and other applications.
• The use of 1550 nm probes and standard components opens new avenues for accessible THz technology.