Sub-100 attosecond timing jitter from low-noise passively mode-locked solid-state laser at telecom wavelength

Area of Science:

• Optics and Photonics
• Laser Physics
• Solid-State Lasers

Background:

• Passively mode-locked diode-pumped solid-state lasers (DPSSLs) are crucial for generating high-quality optical pulse trains.
• Minimizing timing jitter in these lasers is essential for applications requiring precise timing, such as microwave generation.
• Existing fiber laser technologies face limitations in achieving extremely low phase noise.

Purpose of the Study:

• To characterize and report the ultralow timing jitter of 100 MHz pulse trains from passively mode-locked DPSSLs.
• To investigate and compare measured timing jitter with theoretical noise sources.
• To assess the potential of DPSSLs for low phase noise microwave generation.

Main Methods:

• Generation of 100 MHz pulse trains using two identical passively mode-locked DPSSLs emitting at 1556 nm.
• Measurement of timing jitter using a balanced optical cross-correlator as a timing discriminator.
• Theoretical investigation of potential noise sources and comparison with measured jitter power spectral density.

Main Results:

• Measured ultralow timing jitter of 83 attoseconds (as) integrated from 10 kHz to 50 MHz for one DPSSL.
• Demonstrated extremely low intensity noise alongside the low timing jitter.
• Multiple measurement techniques confirmed consistent jitter results.

Conclusions:

• The measured timing jitter, while ultralow, remains above the quantum limit, indicating room for technical improvement.
• Passively mode-locked DPSSLs have significant potential to surpass fiber lasers in generating low phase noise microwaves.
• Further optimization of DPSSLs could lead to advancements in high-precision timing applications.