Sub-100  fs Tm:MgWO_4 laser at 2017  nm mode locked by a graphene saturable absorber

Abstract

We present the first sub-100 fs bulk solid-state laser in the 2-μm spectral range employing the monoclinic Tm-dopedMgWO crystal as an active medium. By applying a graphene-based saturable absorber and chirped mirrors for dispersion management, stable self-starting mode-locked operation at 2017 nm was achieved. Nearly Fourier-limited pulses as short as 86 fs featuring a bandwidth of 53 nm were generated at a repetition rate of 76 MHz. A pulse energy of 1.1 nJ was achieved at 87 MHz for a pulse duration of 96 fs. The mode-locked Tm:MgWO laser exhibits excellent stability with a fundamental beat note extinction ratio of 80 dBc above noise level.

2D Layered Materials: Synthesis, Nonlinear Optical Properties, and Device Applications

“…This work promotes the application of graphene and other layered materials in mode‐locked solid‐state lasers. Up to now, plenty of mode‐locked solid‐state lasers using layered materials such as graphene, TMDCs, and BP have been achieved, as shown in Table . It can be seen that these lasers have excellent performance in pulse width, repetition rate, and pulse energy, which is not inferior to similar lasers.…”

“…In order to obtain laser pulses at different wavelengths, the researchers used different gain media in the abovementioned solid‐state lasers, including Nd:YAG, Yb:KGW, Nd:GdVO 4 , Cr:forsterite, Tm:YAP, Tm:CLNGG, Ti:sapphire, Tm:Lu 2 O 3 , Cr:ZnSe, Yb:GAGG, Cr:YAG, Nd:YVO 4 , Cr:ZnS, Yb:YAG, Cr:LiSAF, Yb:CYA, Tm:MgW, Pr:GdLiF 4 , and Yb,Lu:CALGO . Using abundant gain media and layered materials, the researchers have extended the operation wavelength of mode‐locked solid‐state lasers from visible light to near infrared, even 3 µm mid‐infrared band.…”

Saturable Absorption in 2D Nanomaterials and Related Photonic Devices

“…Due to the strong and wide‐spectral SA response, graphene was widely utilized by the laser community to achieve mode‐locked operation in fiber and bulk lasers. The first sub‐100 fs bulk solid‐state laser using graphene as a saturable absorber was fabricated by the Petrov group in the 2 µm spectral range utilizing a monoclinic Tm 3+ ‐doped MgWO 4 crystal as the active medium . Stable, self‐starting mode‐locked operation was achieved at mid‐infrared with nearly Fourier‐limited pulses as short as 86 fs .…”

“…The first sub‐100 fs bulk solid‐state laser using graphene as a saturable absorber was fabricated by the Petrov group in the 2 µm spectral range utilizing a monoclinic Tm 3+ ‐doped MgWO 4 crystal as the active medium . Stable, self‐starting mode‐locked operation was achieved at mid‐infrared with nearly Fourier‐limited pulses as short as 86 fs . The first all‐fiber stretched‐pulse laser operating beyond 2 µm with nanomaterial‐based SA was reported by Pawliszewska et al .…”

Generation of 84-fs pulses from a mode-locked Tm:CNNGG disordered garnet crystal laser

“…They present efficient tools for the investigation of the dynamics of physical systems on very short time scales [1], and can be used for synchronous pumping of mid-IR optical parametric oscillators and seeding of neardegenerate optical parametric chirped-pulse amplifiers [2] employed for high-order harmonics generation [3]. However, so far, using Tm-or Ho-doped bulk materials (crystals, ceramics, or glasses), sub-100 fs pulses have been reported only with a Tm:MgWO 4 crystal (87 fs) and a Tm:Lu 2∕3 Sc 1∕3 2 O 3 "mixed" ceramic (63 fs) [4,5]. Therefore, exploring novel solid-state laser media for the generation of ultrashort pulses near 2 μm down to the few-cycle limit is of great importance.…”