Browse Prior Art Database

Electron Beam Pumped Solid State Scan Laser

IP.com Disclosure Number: IPCOM000077341D
Original Publication Date: 1972-Jul-01
Included in the Prior Art Database: 2005-Feb-25
Document File: 2 page(s) / 32K

Publishing Venue

IBM

Related People

Dreyfus, RW: AUTHOR [+2]

Abstract

A semiconductor laser is pumped by an electron beam, the latter being deflected by cathode-ray tube (CRT) type deflection plates, so that the scanned region defines the lasing region of the semiconductor. Scanning of the laser beam is achieved by changing the electrical signal on the deflection plates.

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Electron Beam Pumped Solid State Scan Laser

A semiconductor laser is pumped by an electron beam, the latter being deflected by cathode-ray tube (CRT) type deflection plates, so that the scanned region defines the lasing region of the semiconductor. Scanning of the laser beam is achieved by changing the electrical signal on the deflection plates.

As seen in Fig. 1, an electron gun 2, having the conventional X and Y deflection plates 4 and 6, emits a beam 8 of electrons which can be made to dwell at different points along a narrow line 10 of a semiconductor laser crystal
12. The election gun produces 20-100 keV electrons that are focused to approx. 20 amps/cm/2/. With the electron beam striking a given point on crystal 12 more than 10% of the time, then the typical threshold for optical gain of 1/2 amp/cm/2/ is exceeded and stimulated emission occurs.

As seen in Fig. 1, the laser beam is displaced only in the Y direction to achieve linear scanning and the angle (theta) the lasing beam makes with the X- axis is fixed. However, theta is made variable by sweeping both X and Y voltages in phase. The change in relative amplitude of the voltages changes the angular orientation of the linear excitation region. The circuit of Fig. 2 uses one input voltage to vary the amplitude ratio of the X and Y input voltages to control the beam angle theta.

In the case of short-lived excited states, a variant of this device is applicable. When the electron beam sweeps fast enough for t...