Q SWITCHED LASERS

• US 3,831,106 A
• Filed: 02/07/1973
• Issued: 08/20/1974
• Est. Priority Date: 02/11/1972
• Status: Expired due to Term

• Current Assignee: Ferranti International, PLC
• Original Assignee: Ronald Douglas Ward
• Inventors: Ward, Ronald Douglas
• Primary Examiner(s): Sikes, William L.
• Application Number:
  US05/330,405
• Time in Patent Office: 559 Days
• Field of Search: 331/94.5
• US Class Current: 372/12
• CPC Class Codes: H01S 3/115 using intracavity electro-optic devices

Abstract

A Q-switched laser has its optical cavity defined by two rightangled prisms arranged with their hypotenuse faces towards one another and normal to the optical axis of the laser. The apex lines of the two prisms are perpendicular to one another. The optical cavity contains the laser active medium and means for exciting the medium, and also an electro-optic birefringent Qswitching device aligned with its fast axis parallel to the apex line of one of the prisms. A beam-splitting polariser is located between the Q-switching device and one prism.

Claims

1. A Q-switch laser which includes a pair of right-angled prisms arranged with their hypotenuse faces directed towards one another and substantially normal to the laser optical axis and with their right-angle apex lines substantially perpendicular to one another to define an optical cavity, a laser active medium located within the optical cavity, means for stimulating the active medium to cause laser action, an electro-optical birefringent Q-switching device located within the optical cavity with its fast axis parallel to the apex line of one of said prisms, and a beamsplitting polariser located between the laser active medium and the Q-switching device with its pass plane at substantial angles to the fast and slow axes of the Q-switching device.

2. A laser as claimed in claim 1 in which an output beam of radiation is diverted from the optical cavity by the beam-splitting polariser, the power in the output beam being determined by the angles between the pass plane of the polariser and the fast and slow axes of the Q-switching device.

3. A laser as claimed in claim 1 in which the beam-splitting polariser is arranged with its pass plane at 45* to the fast and slow axes of the Q-switching device.

4. A laser as claimed in claim 1 in which the beam-splitting polariser is a Nicol prism.

5. A laser as claimed in claim 1 in which the laser active medium is a solid medium, the means for stimulating the active medium being at least one high-intensity light sourCe.