27 research outputs found
Design of an Efficient Pumping Scheme for Mid-IR Dy3+:Ga5Ge20Sb10S65PCF Fiber Laser
This letter illustrates the design of a novel medium infrared (Mid-IR) laser based on a photonic crystal fiber made of dysprosium-doped chalcogenide glass, Dy3+:Ga5Ge20Sb10S65. In order to perform a realistic investigation, the simulation is performed by taking into account the spectroscopic parameters measured on the rare earth-doped glass sample. The simulated results show that an optical beam emission close to 4400-nm wavelength can be obtained by employing two pump beams at 2850 nm (pump #1) and 4092 nm (pump #2) wavelengths. As example, for the pump powers of 50 mW (pump #1) and 1 W (pump #2), the input mirror reflectivity of 99%, the output mirror reflectivity of 30%, and the optical cavity length of 50 cm, a signal power close to 350 mW at the wavelength of 4384 nm can be generated. This result indicates that the designed source configuration is feasible for high beam quality Mid-IR light generation and it is efficient enough to find applications in optical free propagation links, optical remote sensing, and medicine
Novel pumping schemes of Mid-IR photonic crystal fiber lasers for aerospace applications
The paper illustrates the design of two pumping schemes for Mid-IR lasers based on photonic crystal fibers (PCFs) made of dysprosium doped chalcogenide glass Dy3+:Ga5Ge20Sb10S65. The simulation is performed by taking into account the spectroscopic parameters measured on the rare earth-doped glass sample in order to perform a realistic feasibility investigation. The first pump scheme provides an optical beam emission close to 4400 nm wavelength by employing two pump beams at the wavelengths close to 2800 nm and 4100 nm, respectively. The second pump scheme allows beam emission close to 4400 nm wavelength via a 1700 nm pump, its efficiency is increased by including a suitable optical amplifier after the laser cavity. The proposed light sources based on chalcogenide glass photonic crystal fibers (PCFs) doped with Dy3+ ions are investigated via a home-made numerical model based on the coupled mode theory and solving the rare earth rate equations. A number of promising applications in different areas such as satellite remote sensing and aerospace, biology, molecular spectroscopy and environmental monitoring are feasible
Specific trends in phosphate glass crystallization
This paper focusses on investigating and comparing the congruent crystallization of phosphate glasses with different degrees of polymerization. The study was performed both on powders, with different size fractions, and coarse particles which can be assimilated to bulk. From DSC experiments, corroborated by SEM analysis, it was demonstrated that LiPO3 crystallizes from surface whereas LiGe2(PO4)3 crystallizes in the whole volume. Sn2P2O7 presented both phenomena, the nucleation time lag being short enough to observe internal crystallization at the laboratory time scale. Using the non-isothermal Ozawa method, the kinetic parameters of the overall devitrification process were determined in terms of the Avrami exponent and of the activation energy for crystallization. The temperature of the maximum nucleation rate was calculated by using the nucleation adiabatic theory. For the achievement of this calculation, the heat capacity temperature dependence up to melting was determined from DSC experiments. The results were found in a good agreement with the SEM observation and the results of the non-isothermal crystallization study.acceptedVersionPeer reviewe
Third order nonlinear optical characterization of new chalcohalogenide glasses containing lead iodine
International audienc
Nonlinear optical properties of chalcogenide glasses: comparison between Mach–Zehnder interferometry and Z-scan techniques
International audienc
Experimental evidence of positive and negative nonlinear refractive index change in As/sub 2/Se/sub 3/
International audienc
TWO- AND THREE-PHOTON NONLINEAR ABSORPTION IN As 2 Se 3 CHALCOGENIDE GLASS: THEORY AND EXPERIMENT
International audienc
Heat capacities of crystalline and glassy lithium metaphosphate up to the transition region
International audienc
Chalcogenide glasses as solid state optical limiters at 1.064 ÎĽm
International audienc