High-power, passively mode-locked Nd:GdVO_4laser using single-walled carbon nanotubes as saturable absorber

Abstract

We use a new (to our knowledge) fabrication method of a single-walled carbon nanotube (SWCNT) absorber without polymer to sustain high-power illumination. Using a series of saturable absorbers (SAs) incorporating different amounts of SWCNTs, we demonstrate mode-locking for a Nd:GdVO₄ laser in the 1 μm spectral range. Continuous-wave mode-locking (CWML) pulses with a maximum output power of 3.6 W at 1063 nm and high noise extinction of 61 dB has been achieved to give the highest pulse peak power of 3.6 kW and pulse energy of 30 nJ under 15 W pumping. To our knowledge, this is the highest CWML output power with SWCNT-SAs reported. The measured nonlinear absorption of the SWCNT-SAs shows a modulation depth of ~3% with subpicosecond recovery time.

High-quality and Large-size Topological Insulator Bi2Te3-Gold Saturable Absorber Mirror for Mode-Locking Fiber Laser

“…4(b), the pulse-to-pulse separation was measured to be 49.8 ns, corresponding to fundamental frequency of 20.1 MHz, which matched with the cavity round-trip time. The loss from misalignment between SAs and FC/PC connector results in the difficulty for self-starting from QS instability into continuous-wave mode-locking (CW-ML) operation660. After carefully adjusting the contact angle, stable CW-ML occurs at increased output power of 0.65 mW.…”

“…For passively MLFLs, a saturable absorber (SA) is indispensable in shaping the pulses in the temporal domain2. Among the various types of SAs, semiconductor saturable absorber mirror (SESAM)13, single-wall carbon nanotubes (SWCNTs)45678, and graphene910111213 were intensively used in various MLFL schemes. Although SESAMs have been mostly used in laser resonators to generate mode-locked laser pulses, they are expensive, complicated in fabrication processes (e.g., grown on lattice-matched semiconductor substrates with high quality distributed Bragg reflector mirror), and narrow in wavelength tuning range (typically a few tens of nanometers)1.…”

Performance of diode-pumped continuous wave tunable and passively Q-switched Nd,Mg:LiTaO3 laser

“…It has a transmission rate of 84% (see in Fig. 5) and a modulation depth of 2.9% around 1080 nm [21]. After inserting the SWCNT-SA into the laser cavity, stable Q-switched operation is achieved by aligning the cavity carefully.…”

Improvement of Doubly Q-Switching and Mode-Locking Performance with Nd-Doped Mixed Vanadate Crystals

“…Laser Diode Nd:YVO4 [11], and Nd:GdVO4 [12] have been used in diode-pumped solid-state lasers with SWCNT-SA. On the other hand, Too-large emission cross-section and the short fluorescence line widths of vanadate crystals, which limit their energy storage significantly, are serious drawbacks in Q-switching operation regime [13].…”