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Published on: April 25, 2019
Low-threshold self-starting femtosecond Ti:sapphire laser
Weijun Ling1, Yulei Jia, Jinghua Sun
1Laboratory of Optical Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China.
Applied Optics
|April 21, 2006
Summary
A novel Ti:sapphire laser design achieves low-threshold self-starting Kerr-lens mode-locking using a semiconductor saturable-absorber mirror (SESAM). This enables stable femtosecond pulse generation with high average power, demonstrating SESAM advantages for low-power operation.
Area of Science:
- Optics and Photonics
- Laser Physics
- Materials Science
Background:
- Kerr-lens mode-locking (KLM) is a crucial technique for generating ultrashort laser pulses.
- Achieving low-threshold, self-starting KLM operation is desirable for practical applications.
- Semiconductor saturable-absorber mirrors (SESAMs) offer a promising method for initiating and stabilizing mode-locking.
Purpose of the Study:
- To demonstrate a low-threshold, self-starting Kerr-lens mode-locked Ti:sapphire laser.
- To investigate the performance of a tight-focusing cavity design combined with a SESAM.
- To evaluate the advantages of SESAMs for low-power mode-locking.
Main Methods:
- Utilized a tight-focusing cavity design for the Ti:sapphire laser.
- Incorporated a semiconductor saturable-absorber mirror (SESAM) for mode-locking.
- Employed output couplers of 3% and 12% to determine mode-locking thresholds.
- Characterized femtosecond pulse duration, bandwidth, and average power.
Main Results:
- Achieved mode-locking thresholds as low as 390 mW (3% output coupler) and 600 mW (12% output coupler).
- Generated stable femtosecond laser pulses with 17 fs duration and 47 nm bandwidth.
- Obtained an average power of 114 mW at a pump power of 1.2 W.
- Demonstrated stable mode-locking operation over a wide pump power range (600 mW to 4.8 W at 12% output coupling).
Conclusions:
- The demonstrated Ti:sapphire laser design enables efficient, low-threshold, self-starting Kerr-lens mode-locking.
- The combination of a tight-focusing cavity and SESAM is effective for generating high-quality femtosecond pulses.
- SESAMs provide significant advantages for achieving low-power mode-locking operation in Ti:sapphire lasers.
