Watt-level high-power passively Q-switched laser based on a black phosphorus solution saturable absorber

Abstract

A novel black phosphorus (BP) solution saturable absorber (SA) is fabricated by the liquid-phase-exfoliated method and successfully used for passively Q-switched (QS) Nd:YVO 4 laser. Compared with a traditional solid SA, a BP solution SA possesses more excellent optical transparency and higher damage resistance. The shortest pulse duration and highest average output power are measured to be 119 ns and 1.23 W, respectively. To the best of our knowledge, both of them are the best results among QS solid-state lasers with BP-based absorbers so far. High power Q-switched (QS) laser pulses of nanosecond time duration always have extensive applications in the fields of material processing, biomedicine, spectroscopy, and so on. Therefore, the manufacture of QS solid-state lasers (SSLs) with high output power and narrow pulse width is extremely essential. As a significant technique for generating nanosecond laser pulses, passively Q-switching in SSLs depends absolutely on high-quality saturable absorbers (SAs) [1,2] . Since 2009, due to the intrinsic zero bandgap and large nonlinear absorption wavelength range [3][4][5] , Graphene has been extensively applied to the pulse generation of various wave bands [3][4][5][6][7] . The successful applications of graphene inspire researchers to explore other graphene-like two-dimensional (2D) materials such as topological isolators (TIs) [8,9] and transition metal dichalcogenides (TMDs) [10,11] . Over the last few years, these emerging 2D materials have experienced a rapid development. Many kinds of SAs fabricated with 2D materials are used for mode locking or Q-switching technology in different lasers [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] . Recently, as another kind of 2D nanomaterial, black phosphorus (BP) has attracted significant attention in the field of nonlinear optical materials. Compared with other allotropes of phosphorus, BP possesses a "wrinkled" layered structure and a relatively strong thermodynamic stability [23,24] . In addition, BP is a highmobility semiconductor with a direct bandgap sensitivity depending on the number of layers from 0.3 (bulk) to 2.0 eV (single layer) that exactly fill the gap between the zero bandgap of graphene and the wide bandgap (1.0-2.0 eV) of TMDs [25] . The narrower bandgap of BP makes itself act as the SA, which has been used in a broader wavelength operation range of 4-0.8 μm [26,27] . In addition, like graphene, BP SA owns the same excellent nonlinear optical response and easy fabrication process [13,23] . Q-switching or mode locking in SSLs using graphenelike absorbers [9,15,16,18,20,21,26,27,[29][30][31][32][33][34][35] are listed in Table 1. These absorbers are made by growing nanomaterials by chemical vapor deposition and transferring themon a mirror or depositing them on the quartz substrate by the spin-coating method. However, even if the reports are numerous, the average output power of the pulsed lasers is very limited. The maximum average output power reported is only 820 mW [33] (Q-switching) [29] (...

High Power Self-Q-Switching in Nd:LuAG Laser

“…However, the complicated fabrication process of the SAs such as SESAMs (semiconductor saturable absorber mirror) still results in high cost [3,4]. Even though a series of new materials have excellent properties of saturable absorption, such as graphene [5][6][7], carbon nanotube [8], topological insulators [9][10][11], transition metal dichalcogenides [12][13][14], black phosphorus [15][16][17], and gold nanorods [18], their practical characteristics need more time to verify.…”

Diode-Pumped Solid-State Q-Switched Laser with Rhenium Diselenide as Saturable Absorber

“…Few-layer materials are of great importance to researches and applications due to their unique optical and electronic characteristics. Current researches on few-layer materials are principally focused on graphene, insulating hexagonal boron nitride (hBN), topological insulators (TIs), black phosphorus (BP), and transition metal dichalcogenides (TMDs) [1][2][3][4][5][6]. Among these materials, TMDs are a large family, which exhibits a variety of photo-electric properties and offers a wide range of applications in broad research fields [5,6].…”

1.3 μm passively Q-switched mode-locked laser with Fe3O4 nanoparticle saturable absorber

“…The use of gaphene as the 2D nanomaterial SA to realize pulse output in a laser, provides a new idea for researchers [7]. Other nanomaterials being used as saturated absorbers then emerged in quick succession: carbon nanotube, transition metal dichalcogenides (TMDs), topological insulators (TI), black phosphorus (BP), transition metal oxides (TMOs) and others [8][9][10][11][12].…”