Red and orange laser operation of Pr:KYF4 pumped by a Nd:YAG/LBO laser at 469.1nm and a InGaN laser diode at 444nm

We report the basic luminescence properties and the continuous-wave (CW) laser operation of a Pr3+-doped KYF4 single crystal in the Red and Orange spectral regions by using a new pumping scheme. The pump source is an especially developed, compact, slightly tunable and intra-cavity frequency-doubled diode-pumped Nd:YAG laser delivering a CW output power up to about 1.4 W around 469.1 nm. At this pump wavelength, red and orange laser emissions are obtained at about 642.3 and 605.5 nm, with maximum output powers of 11.3 and 1 mW and associated slope efficiencies of 9.3% and 3.4%, with respect to absorbed pump powers, respectively. For comparison, the Pr:KYF4 crystal is also pumped by a InGaN blue laser diode operating around 444 nm. In this case, the same red and orange lasers are obtained, but with maximum output powers of 7.8 and 2 mW and the associated slope efficiencies of 7 and 5.8%, respectively. Wavelength tuning for the two lasers is demonstrated by slightly tilting the crystal. Orange laser operation and laser wavelength tuning are reported for the first time

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

Design of an Efficient Pumping Scheme for Mid-IR Dy3+:Ga5Ge20Sb10S65 PCF 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. The pump beams can be provided by commercial quantum cascade lasers. 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

Evaluation of Amniotic-Derived Membrane Biomaterial as an Adjunct for Repair of Critical Sized Bone Defects

Introduction. Autogenous bone graft is the gold standard in reconstruction of bone defects. The use of autogenous bone graft is problematic because of limited bone as well as donor site morbidity. This study evaluates a novel biomaterial as an alternative to autogenous bone graft. The biomaterial is amniotic membrane, rich in growth factors. Methods. Twenty-one adult male Sprague-Dawley rats were implanted with biomaterial using the rat critical size femoral gap model. After creation of the critical size femoral gap animals were randomized to one of the following groups: Group 1 (control): gap left empty and received no treatment; Group 2 (experimental): the gap was filled with commercially available bone graft; Group 3 (experimental): the gap was filled with bone graft plus NuCel amniotic tissue preparation. Results. The experimental groups demonstrated new bone formation compared to controls. The results were evident on radiographs and histology. Histology showed Group 1 controls to have 11.1% new bone formation, 37.8% for Group 2, and 49.2% for Group 3. These results were statistically significant. Conclusions. The study demonstrates that amniotic membrane products have potential to provide bridging of bone defects. Filling bone defects without harvesting autogenous bone would provide a significant improvement in patient care