We have studied a laser diode self-injection locking to the modes of whispering gallery mode microresonator (WGMM) in a wide range of parameters and derived several regularities allowing optimization of the locking process. In this work we investigated in detail the optimization process, based on the thermal nonlinearity of the WGMM modes, when the laser frequency is tuned smoothly to the WGMM frequency (adiabatic tuning).
Lasing on 3p-3s transitions of neutral neon atoms upon pumping neon and its mixtures by a pulsed inductive discharge was obtained. The emission spectrum, depending on the pumping conditions, consisted of individual lines with wavelengths of 540.1,585.3, and 614.3 (594.4) nm.
We demonstrate experimentally that a sandwich-like structure comprising a thin layer of lithium niobate clamped between two Si prisms of total internal reflection can serve as an efficient converter of nJ-energy level laser pulses from a femtosecond optical oscillator to a high-quality beam of broadband terahertz radiation. The converter has an additional advantage of workability at different laser wavelengths.
The formation of binary amorphous-crystalline periodic structures on the surface of Ge2Sb2 Te5 thin film during a single pass of a femtosecond laser beam has been studied. We recorded biphase stripes up to several mm long consisted of 50 parallel amorphous/crystalline lines oriented perpendicular to the light polarization. These stripes had a period equal to the recording beam wavelength (1030 nm) and exhibited diffraction grating behavior due to the remarkable optical contrast. We performed diffraction simulations and obtained good agreement with the experimental results for a beam (532 nm) diffracted by the recorded grating.
An experimental and theoretical study of the processes occurring in the ytterbium-erbium doped fiber amplifier (YEDFA) has been carried out. Among them are up-conversion, energy-transfer, secondary energy-transfer (SET) processes. The introduced model makes it possible to analyze the amplification regimes of the amplifier and optimize YEDFA characteristics. While taking into account the SET process the calculation results demonstrated good agreement with experimental data in a wide range of input signal and pump powers.
