Ultrafast pulse generation at 115 fs with a high peak power of 0.24 MW aided with Bi2Te3 2D nanomaterials

Abstract

The generation of mode-locked pulses in the femtosecond region with high output power has shown its demand in various applications, such as laser cutting. Traditional active mode-locking approaches, such as acousto-optic modulators, can be challenging, particularly in timing setups. Alternatively, a semiconductor saturable absorber mirror (SESAM) was used in the passive approach. Yet, its cost and sensitivity to high-humidity environments led to the adoption 2D nanomaterials, which offer robust systems with notable modulation depths. Despite these advancements, most mode-locked lasers using 2D nanomaterials produced pulses in the picosecond region with average output power in the milliwatts (mW) range, limiting their applications. This work addresses the need for higher output power, which presents a detailed methodology for generating stable mode-locked pulses at 1 µm, achieving an average output power > 690 mW, a signal-to-noise ratio (SNR) of 52 dB, and a pulse width of 115 fs. Utilizing Bi₂Te₃ as a 2D nanomaterial saturable absorber, this work demonstrates a significant improvement in pulse stability and SNR, highlighting the potential for advanced applications.