Arthur Maitland

A copper HyBrID laser of 120 W average output power and 2.2% efficiency

A copper HyBrID laser (λ=510.6, 578.2 nm) is reported which produced 121 W at 2.2% efficiency (based on stored energy), with a pulse recurrence frequency of 18 kHz. For an output power of 100 W, the efficiency was 2.6%. A 21% enhancement in output power was achieved by eliminating parasitic stimulated emission due to back-reflection from the silica discharge-tube windows.

A high-power high-efficiency Cu-Ne-HBr (λ = 510.6, 578.2 nm) laser

Abstract A high-power copper bromide laser, which utilizes the technique of in situ production of CuBr by reaction of copper of HBr, is reported. The 45 mm bore copper HyBrID (Hydrogen Bromide In Discharge) laser has produced a maximum average output power at 510.6 and 578.2 nm of 94W at 21 kHz pulse recurrence frequency, with an efficiency (based on stored energy) of 1.5%. The corresponding specific output power was 52 mW cm-3. An efficiency of an average output power of 40 W. Laser oscillation can be obtained less than 15 minutes after a cold start-up, with full power attained 5 min later.

A copper HyBrID laser with 2 W/cm/sup 3/ specific average output power

A copper HyBrID laser (/spl lambda/510.6, 578.2 nm) is reported, which produced an average output power of 9.5 W from an active volume of just 4.77 cm/sup 3/. These figures correspond to a record specific average output power for copper lasers of any type of 2.0 W/cm/sup 3/. >

Radial and temporal laser pulse profiles in a 0.2-kW average power copper HyBrID laser

The transverse profiles and evolution of the laser intensities of a high-power copper HyBrID laser (510.6 nm, 578.2 nm) are presented. Both the radial profiles and temporal evolutions of the laser pulse intensities are markedly different in a large- bore (6 cm) HyBrID laser than in conventional elemental metal copper vapor lasers of similar dimensions. The differences in laser intensity distributions and their temporal evolution are attributed to the electron-attaching properties of hydrogen and bromine in the laser buffer gas mixture of a HyBrID laser. The significantly low conductivity of the gas in a HyBrID laser means that the plasma skin effect is relatively weak and does not influence the development of laser oscillation to any great extent; oscillation in a 6 cm bore HyBrID laser begins on the tube axis first and at the wall 3-4 ns later; the time-averaged laser intensity peaks on the tube axis.

A microwave-excited strontium-ion (λ430.5 nm) recombination laser

Laser oscillation on the 430.5 nm transition of Sr+, which replies on three-body electron-ion recombination for its excitation, has been achieved in a pulsed, selfheated, microwave-pumped discharge.

A simple and reliable 100 kHz all solid state thyratron driver for pulsed laser applications

An inexpensive, high repetition rate (1 to 100 kHz), thyratron driver has been developed which employs a single solid state switch. The driver delivers an unloaded 1.5 kV positive trigger pulse superimposed onto a negative 300 V recovery voltage to the thyratron trigger grid. The voltage rate of rise (>10 kV mu s-1) results in low-trigger jitter (less than the 5 ns resolution of the diagnostic apparatus). The driver has been used to trigger a thyratron in the excitation circuit of a copper hybrid laser at a pulse recurrence frequency of 70 kHz.

A copper vapour laser using metallic walls for discharge confinement

The authors have demonstrated a discharge heated copper vapour laser (CVL) which uses metal to confine a longitudinal discharge. The design allows the amount of thermal insulation and/or the bore diameter to be easily altered. By using a refractory metal such as molybdenum or tantalum in the hottest part of the laser, temperatures significantly higher than are possible using ceramic materials are potentially attainable.

Simplification of spectra by electro-optic gating of the radiant emission from laser-produced plasmas

A method of gating the emission from the laser-produced plasmas of solid targets is described. A Pockels cell is operated between parallel polarisers and used as an optical shutter. If the shutter is opened after the continuum and multiply ionised species emission has subsided, a considerably simplified spectrum containing only singly ionised and atomic lines is obtained. Gated spectra from Mg, Al and Fe plasmas are shown.

Novel high-speed communication system

Ultra-high data rate optical communication links require multiplexing to separate channels. This is usually achieved electronically, limiting the data rate to the speed of the driving electronics. We describe a new means of optical-frequency division multiplexing which makes use of the spatial and frequency modulating characteristics of acoustooptic Bragg cells. A two channel proof-of-principal experiment is presented.

Bragg Cell Diffraction in Resonant Cavities

Abstract Steier et al. [1] have shown that the diffraction efficiency of a stationary grating may be improved by placing the grating in a resonant cavity. In this paper we describe the diffraction of light by a Bragg cell in a resonant cavity. Large improvements in diffraction efficiency are shown to be possible if scattering losses on the surface of the cell can be kept small. The effects of introducing gain into the cavity are calculated and the changes in bandwidth, resolution and dynamic range are discussed for the system when used as a radiofrequency spectrum analyser. A multichannel fibre optic system has been designed and is described.