Relative intensity noise reduction for noise-like pulses based on synchronous intensity modulation

• Published in: Optics communications 2024-10, Vol.569, p.130850, Article 130850
• Main Authors: Wang, Peng, Wang, Chuncan, Li, Jing
• Format: Article
• Language: English
• Subjects: Intensity modulation; Mode-locked fiber laser; Noise-like pulse; Relative intensity noise
• ISSN: 0030-4018; 1873-0310
• DOI: 10.1016/j.optcom.2024.130850

Extra-cavity synchronous intensity modulation is a straightforward and effective approach to suppress the full-bandwidth relative intensity noise (RIN) for noise-like pulse (NLP) fiber lasers. In this work, the picosecond NLPs are produced by a homemade Er/Yb co-doped mode-locked fiber laser and subsequent optimized by the synchronous intensity modulation device. The photodetector (PD) and electro-optical modulator (EOM) allow the real-time measurement and modulation for each optical pulse. A detailed description of key parameters for components is presented. The impact of DC bias voltage and RF signal amplitude on resulting RIN is experimentally investigated. We demonstrate a noteworthy reduction in RIN from 5.62% before synchronous intensity modulation to 1.91% afterward. Numerical investigations suggest that this method is potential to suppress RIN to below 1% under ideal conditions. The key factor in RIN reduction is correct operating region and high photoelectric-conversion linearity. The synchronous intensity modulation is an effective method to obtain low-RIN NLP laser sources, valuable for some practical applications. •Full-bandwidth relative intensity noise suppression based on synchronous intensity modulation.•The real-time measurement and modulation for each optical pulse.•A noteworthy reduction in RIN from 5.62% before synchronous intensity modulation to 1.91% afterward.•Correct operating region and high photoelectric-conversion linearity benefit to RIN reduction.