CW-pumped evanescent amplification based on side-polished fiber with heavily Er3+-doped glass overlay

A novel diffractive-pumping scheme is proposed to improve the evanescent amplification using blazed fiber grating for the first time. We also investigate the cw-pumped-evanescent amplification at 1.55 mu m wavelength with the relative optical gain pumped at 1480 nm of around 2 dB based on side-polished fiber with the effective interaction length as long as 16 mm and with a heavily Er3+-doped (N-Er(3+) > 1.19 x 10(21) ions/cm(3)), low refractive index (n(1550) < 1.47) glass overlay, which has no concentration quenching (tau(f) = 9.0 ms).

Infrared (1.2-1.6 mu m) luminescence in Yb, Cr : YAG with 940 nm diode pumping

Infrared (1.2-1.6 mum) luminescence in a yttrium aluminium garnet (YAG) crystal, co-doped with Yb (10 at.%) and Cr (0.05 at.%) ions, was investigated under CW laser diode pumping (lambda = 940 nm). The Cr4+ emission band was observed with its peak at 1.35 mum and measured to be about 6% with respect to Yb3+ IR luminescence (lambda = 1.03 mum). Analysis of the crystal absorption and luminescence spectra allows one to conclude that Yb3+-Cr4+ energy transfer is a mechanism responsible for the B-3(2)(T-3(2))-B-3(1)((3)A(2)) emission of Cr4+ ions. This crystal is promising as an efficient source of the near infrared emission. (C) 2004 Elsevier B.V. All rights reserved.

Infrared (1.2-1.6 mu m) luminescence in Cr4+: Yb3Al5O12 single crystal with 940 nm diode pumping

Infrared (1.2-1.6 mu m) luminescence in a ytterbium aluminium garnet (YbAG) crystal, doped with Cr (0.05 at.%) ions, was investigated under CW laser diode pumping (lambda = 940 nm). The Cr4+ emission band was observed with its peak at 1.34 mu m and measured to be about 1.3 times with respect to Yb3+ IR luminescence (lambda = 1.03 mu m). We demonstrate that for the excitation wavelength of 940 nm Yb3+ ions act as sensitizers of the B-3(2)(T-3(2))-B-3(1)((3)A(2)) emission of Cr4+ ions. This crystal is promising as a high-efficient system for tunable laser (1.2-1.6 mu m) output. (c) 2004 Elsevier B.V. All rights reserved.

Near infrared broadband emission of bismuth-doped aluminophosphate glass

Near infrared broadband emission characteristics of bismuth-doped aluminophosphate glass have been investigated. Broad infrared emissions peaking at 1210nm, 1173nm and 1300nm were observed when the glass was pumped by 405nm laser diode (LD), 514nm Ar+ laser and 808nm LD, respectively. The full widths at half maximum (FWHMs) are 235nm, 207nm and 300nm for the emissions at 1210nm, 1173nm and 1300nm, respectively. Based on the energy matching conditions, it is suggested that the infrared emission may be ascribed to P-3(1) --> P-3(0) transition of Bi+. The broadband infrared luminescent characteristics of the glasses indicate that they are promising for broadband optical fiber amplifiers and tunable lasers. (C) 2005 Optical Society of America.

Superbroadband 1310 nm emission from bismuth and tantalum codoped germanium oxide glasses

Near-infrared broadband emission from bismuth-tantalum-codoped germanium oxide glasses was observed at room temperature when the glasses were pumped by an 808 nm laser diode. The emission band covered the 0, E, S, C, and L bands (1260-1625 nm), with a maximum peak at similar to 1310 nm, a FWHM broader than 400 nm, and a lifetime longer than 200 lis. The observed broadband luminescence was attributed to bismuth clusters in the glasses. Bismuth-tantalum-codoped germanium oxide glass might be promising as amplification media for broadly tunable lasers and wideband amplifiers in optical communications. (c) 2005 Optical Society of America.

Blue-yellow ZnO homostructural light-emitting diode realized by metalorganic chemical vapor deposition technique

We report on the realization of ZnO homojunction light-emitting diodes (LEDs) fabricated by metalorganic chemical vapor deposition on (0001) ZnO bulk substrate. The p-type ZnO epilayer was formed by nitrogen incorporation using N2O gas as oxidizing and doping sources. Distinct electroluminescence (EL) emissions in the blue and yellow regions were observed at room temperature by the naked eye under forward bias. The EL peak energy coincided with the photoluminescence peak energy of the ZnO epilayer, suggesting that the EL emissions emerge from the ZnO epilayer. In addition, the current-voltage and light output-voltage characteristics of ZnO homojunction LEDs have also been studied. (c) 2006 American Institute of Physics.

Ti:sapphire laser pumped high average power laser crystal Nd:GGG with high efficiency output

High-quality neodymium doped GGG laser crystals have been grown by Czochralski (Cz) method. Results of Nd:GGG thin chip laser operating at 1.064 μm pumped by Ti:sapphire laser operating at 808 nm were reported. The slop efficiency was as high as 20%.

室温下光纤耦合二极管泵浦Tm：YAP激光器

为实现室温下小型化、高效率的1.9μm激光输出,采用793.5 nm激光二极管泵浦Tm：YAP晶体,晶体采用热电制冷及风冷的方式控制在18℃,采用1∶1的聚焦耦系统,获得功率为2.2 W、中心波长为1928 nm的激光输出,光光转换效率为31%,斜率效率达41%。对影响激光输出的耦合输出率、腔型、腔长、晶体工作温度等因素进行了实验分析,实验结果表明：输出功率的变化与温度基本成线性关系,当增加激光谐振腔长时,由于高阶模式损耗加大以及晶体热透镜效应的加重导致腔内损耗加大,输出功率和斜率效率都有所下降。

Judd-Oflet analysis of spectrum and laser performance of Ho:YAP crystal end-pumped by 1.91-mu m Tm:YLF laser

The Ho:YAP crystal is grown by the Czochralski technique. The room-temperature polarized absorption spectra of Ho:YAP crystal was measured on a c-cut sample with 1 at% holmium. According to the obtained Judd-Ofelt intensity parameters Omega(2) = 1.42 x 10(-20) cm(2), Omega(4) = 2.92 x 10(-20) cm(2), and Omega(6) = 1.71 x 10(-20) cm(2), this paper calculated the fluorescence lifetime to be 6 ms for I-5(7) -> I-5(8) transition, and the integrated emission cross section to be 2.24 x 10(-18) cm(2). It investigates the room-temperature Ho:YAP laser end-pumped by a 1.91-mu m Tm:YLF laser. The maximum output power was 4.1 W when the incident 1.91-mu m pump power was 14.4W. The slope efficiency is 40.8%, corresponding to an optical-to-optical conversion efficiency of 28.4%. The Ho:YAP output wavelength was centred at 2118 nm with full width at half maximum of about 0.8 nm.

Building up a frequency stabilisation based on a wavemeter for a diode laser and characterisation for a digital mirror device for artificial potentials

It has built and characterised a laser and It has learned what each of the components does. It has been able to run the laser in single-mode and stabilised it around a desired setpoint thanks to a PID controller that It has programmed. It has established a communication between the PID controller programmed in LabVIEW and Arduino Due, the DAC that It has chosen after comparing it with another candidate. It has learned some basics of how the LightCrafter 4500 DMD works. The projected light is the composition of the lights of three LED’s, each of which has a certain on-time. The mirrors chose to be in on- or off-stages depending to the amount of intensity that we want for each colour.