Vertically standing PtSe₂ film: a saturable absorber for a passively mode-locked Nd:LuVO₄ laser

Abstract

The novel vertically standing PtSe 2 film on transparent quartz was prepared by selenization of platinum film deposited by the magnetron sputtering method, and an Nd:LuVO 4 passively mode-locked solid-state laser was realized by using the fabricated PtSe 2 film as a saturable absorber. The X-ray diffraction pattern and Raman spectrum of the film indicate its good crystallinity with a layered structure. The thickness of PtSe 2 film is measured to be 24 nm according to the cross-section height profile of the atomic force microscope image. Highresolution transmission electron microscopy images clearly demonstrate its vertically standing structure with an interlayer distance of 0.54 nm along the c-axis direction. The modulation depth (ΔT ) and saturation fluence (Φ s ) of PtSe 2 film are measured to be 12.6% and 17.1 μJ∕cm 2 , respectively. The obtained mode-locked laser spectrum has a central wavelength of 1066.573 nm, with a 3 dB bandwidth of 0.106 nm. The transform limited pulse width of the mode-locked laser was calculated to be 15.8 ps. A maximum average output power of 180 mW with a working repetition rate of 61.3 MHz is obtained. To the best of our knowledge, this is the first report of the generation of ultrafast mode-locked laser pulses by using layered PtSe 2 as a saturable absorber.

Nonlinear Optical Signatures of the Transition from Semiconductor to Semimetal in PtSe2

“…PtSe 2 , a rising member of the group‐10 transition metal dichalcogenides (TMDC) family, has been demonstrated with a strong interlayer interaction and undergoes a unique evolution from semiconductor to semimetal with increasing layer thickness . It possesses many intriguing properties including an indirect energy bandgap ranging from 0 to 1.2 eV, high carrier mobility and good environmental stability, which suggests that beyond graphene and BP, PtSe 2 can be used as a good candidate in electronic devices, wide spectral response photodetector, and photodiodes, optical switches and saturable absorbers, etc. However, the evolution of nonlinear optical (NLO) properties and ultrafast dynamics with layer thickness, which is crucial for developing high performance photonic devices, has been rarely reported to date.…”

Ultrafast Carrier Dynamics and Bandgap Renormalization in Layered PtSe2

“…Recent studies have shown some intriguing properties of PtSe 2 , such as high charge‐carrier mobility, intrinsic patterning, piezoresistivity, and spin‐layer locking . Moreover, PtSe 2 exhibits great potential in electronic and optoelectronic devices, for example, field effect transistors (FETs), spintronics, mid‐infrared photodetectors, gas sensors, valleytronics, and optical modulators . Despite a number of reports addressing the synthesis, electrical properties, and prototype devices, there is still a lack of understanding regarding the carrier dynamics in layered PtSe 2 on an ultrafast time scale.…”

“…This allows the majority of intense light to pass through and blocks the light with low intensity. This photoinduced response of PtSe 2 can be exploited as a saturable absorber for passive mode‐locking to generate femtosecond laser pulses, especially in mid‐infrared range because of its small bandgap …”

Observation the Multi-Soliton Patterns From the Er-Doped Mode-Locked Fiber Laser Modulated by PtSe2

“…The outstanding high-performance devices based on PtSe 2 have been investigated, such as the pressure and gas sensors [26,27], broadband mid-infrared photodetector [28], and wide spectral photoresponse photodiode [29]. In addition, the PtSe 2 has advantages of high carrier mobility [30][31][32], ambient stable and sizable band gap, all of which filled the gaps of the materials mentioned above. Moreover, PtSe 2 has excellent non-linear optical response, which can provide a candidate to explore the soliton evolution in the passively mode-locked fiber laser.…”