Chromium oxide film for Q-switched and mode-locked pulse generation

Abstract

Chromium oxide (Cr2O3) is a promising material used in the applications such as photoelectrochemical devices, photocatalysis, magnetic random access memory, and gas sensors. But, its nonlinear optical characteristics and applications in ultrafast optics have not been studied yet. This study prepares a microfiber decorated with a Cr2O3 film via magnetron sputtering deposition and examines its nonlinear optical characteristics. The modulation depth and saturation intensity of this device are determined as 12.52% and 0.0176 MW/cm2. Meanwhile, the Cr2O3-microfiber is applied as a saturable absorber in an Er-doped fiber laser, and stable Q-switching and mode-locking laser pulses are successfully generated. In the Q-switched working state, the highest output power and shortest pulse width are measured as 12.8 mW and 1.385 µs, respectively. The pulse duration of this mode-locked fiber laser is as short as 334 fs, and its signal-to-noise ratio is 65 dB. As far as we know, this is the first illustration of using Cr2O3 in ultrafast photonics. The results confirm that Cr2O3 is a promising saturable absorber material and significantly extend the scope of saturable absorber materials for innovative fiber laser technologies.

Noble metal-free SERS: mechanisms and applications

“…Additionally, TMNs can exhibit plasmonic behavior in the visible and near-infrared range under certain conditions, such as variations in optical properties, chemical deposition, and structural size. 23,[96][97][98] For example, Sucheewa et al demonstrated that a hafnium nitride (HfN) thin film created through gas-timed RF magnetron sputtering exhibited an EF of 8.5 × 10 4 for MB molecules, which was largely attributed to an increased "hot spot" effect. The absorbance of the HfN thin film in the longer wavelength range (approximately 500-900 nm) is advantageous for surface plasmon resonance, which greatly enhances the electromagnetic mechanism on the surface.…”

Optical modulation in Er-doped fiber laser delivering dark pulse utilizing side polished fiber coated with Ti3AlC2 as saturable absorber

“…Therefore, they have high temperature resistance like ceramic and have excellent electrical and thermal conductivity like metal. Compared to other materials [28][29][30] MAX phase exhibited low density, high modulus elasticity, good oxidation resistance and high melting point. These properties of MAX phase promote them as promising material to be used in high temperature applications.…”

Third-order optical nonlinearities of Nb4C3 MXene and its application as an ultra-broadband mode-locker

“…35 Q-Switched and mode-locked pulses were generated from the erbium-doped fiber ring cavity with Cr 2 O 3 SA. 36 Dissipative solitons with a pulse width of 1.03 ps were generated as Nb x Re (1Àx) S 2 SA. 37 2D MXenes are early transition metal carbides and nitrides with a chemical formula of M n+1 X n T x (n = 1-3).…”