Showing papers on "Slope efficiency published in 1984"

CW laser pumped emerald laser

Abstract: A CW laser pumped emerald laser is reported, A 34 percent output power slope efficiency is observed with longitudinal pumping by a krypton laser in a nearly concentric cavity The laser has been tuned from 7288 to 8090 nm, Losses in emerald are larger than those of alexandrite determined in a similar cavity Our data also indicate that the excited state absorption minimum is shifted from that of alexandrite

Method for screening laser diodes

Abstract: A method for screening double heterostructure laser diodes before mounting and packaging is disclosed At a normal laser diode operating temperature, a range of pulsed current is passed through the laser diode and the lasing threshold current and slope efficiency of the laser diode are monitored The laser diode is then subjected to a burn-in process in which it is driven at a high junction temperature for an extended time period Subsequently the lasing threshold current and slope efficiency are again monitored by applying the same range of pulsed current at the normal operating temperature If either the threshold current or the slope efficiency have changed by more than a predetermined amount, the laser diode is rejected Otherwise, the laser diode is gauged as likely to have a lifetime greater than a predetermined value at normal operating conditions so warranting further testing prior to installation into a laser package

Room-temperature operation of the vibronic KZnF(3):Cr(3+) laser.

Abstract: True cw laser operation was achieved with the vibronic KZnF3:Cr3+ laser at room temperature. The laser is optically pumped with a krypton laser at 647 and 676 nm. With 1 W of absorbed power the laser is tunable between 785 and 865 nm. A 14% power-output slope efficiency was observed with longitudinal pumping in a folded three-mirror resonator.

Investigation of the laser materials YAlO3:Er and LiYF4:Ho

Abstract: The laser emission of YAlO3:Er at 1.663 mu m was investigated in order to find the best conditions with respect to crystal orientation, Er concentration, and output coupling. Using ten different laser rods the following optimised data have been obtained: b axis laser rod (Pnma notation), 1.25% Er doping, and 85% output mirror reflectivity. The temperature dependence of laser threshold and efficiency was measured between -50 degrees C and 50 degrees C. At room temperature the authors obtained 34 J threshold energy and 0.07% slope efficiency. In addition laser emission of LiYF4:Ho, Er, Tm at 2.065 mu m was investigated. The slope efficiency was 0.22%. Laser emission of YAlO3:Ho, Er, Tm at 2.12 mu m is briefly mentioned.

Diode Pumped Fiber Laser.

Abstract: : This report describes work conducted in the area of single crystal fiber optical devices. Miniature Nd:YAG 1.32 micron lasers were fabricated using both free space (unguided) and single crystal fiber configurations. Bulk lasers with thresholds as low as 19 mw and near optimum slope efficiencies of 36% were demonstrated. Several guided fiber lasers were also successfully brought to oscillation. The best device has a threshold of 12 mw, a slope efficiency of 22%, and a maximum recorded output power at 1.32 micrometers of 22 mw. Fiber scattering properties inferred from these measurements indicate that the crystal fiber used in this work exhibit a much higher quality than the fibers used in earlier phases of this work as a result of improved growth conditions. A theoretical investigation of 1.32 micrometers optically-pumped lasers was also developed for interpretation of experimental data. A feasibility study of Q-switched fiber lasers operating near lambda = 1.06 micrometers was also conducted. Theoretical expressions for the laser output peak power, pulse width and energy were cast in a simple form by implementing the formalism of normalized mode overlap coefficient introduced earlier in this work. Peak powers on the order of 100-500 watts and pulse widths of a few nanoseconds are anticipated for fiber lasers were also reviewed and compared to provide a recommended guideline for future laser work.