Browse Prior Art Database

GaAs Laser Collimator and Circularizer

IP.com Disclosure Number: IPCOM000107596D
Original Publication Date: 1992-Mar-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 2 page(s) / 43K

Publishing Venue

IBM

Related People

Lean, EG: AUTHOR

Abstract

Disclosed is a simple and efficient collimator for GaAs laser. A typical GaAs laser has a divergent angle of 30 degrees normal to the junction plane and 10 degrees in the junction plane. If the laser is located at the focused point of a paraboloidal reflector, as shown in Fig. 1, the laser beam can be collimated by the paraboloidal reflector. The collimated beam will have an aspect ratio of 3 to 1. A beam circularizer can also be integrated into the paraboloidal collimator, as shown in Fig. 2.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

GaAs Laser Collimator and Circularizer

       Disclosed is a simple and efficient collimator for GaAs
laser.  A typical GaAs laser has a divergent angle of 30 degrees
normal to the junction plane and 10 degrees in the junction plane.
If the laser is located at the focused point of a paraboloidal
reflector, as shown in Fig. 1, the laser beam can be collimated by
the paraboloidal reflector. The collimated beam will have an aspect
ratio of 3 to 1.  A beam circularizer can also be integrated into the
paraboloidal collimator, as shown in Fig. 2.

      The advantages of this paraboloidal collimator for GaAs lasers
are the following:
1.   With the same focus point, the collimator has a variable
numerical aperture (NA) which can be close to one.  A GaAs laser can
simply be butted against the base of the collimator at the focal
point.  Independent of the NA of the laser, the output light will be
collimated by the reflector.  This simplifies the alignment problem.
2.   The collimator can also serve as a beam circularizer by
inclining the output surface with an angle alpha.  The angle must be
adjusted for the aspect ratio.