Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

High Efficiency, Polarized GaAs Laser Array

IP.com Disclosure Number: IPCOM000080542D
Original Publication Date: 1974-Jan-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 2 page(s) / 29K

Publishing Venue

IBM

Related People

Wieder, H: AUTHOR

Abstract

Light which emanates from a conventional GaAs laser is usually weakly and randomly polarized. Even double-heterojunction lasers often show low polarization when excited at high-power levels. It is desirable to have laser arrays which emit light that is strongly and uniformly polarized at all power levels. In order to achieve such polarization without sacrificing efficiency of the device or the compactness of the array, it is desirable to provide a cavity structure which allows discrimination of the TE set of modes with respect to the TM set without the use of an external cavity, and without any artifacts which interfere with the device performance. The cavity shown in Fig. 1 accomplishes this discrimination in the desired way.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 58% of the total text.

Page 1 of 2

High Efficiency, Polarized GaAs Laser Array

Light which emanates from a conventional GaAs laser is usually weakly and randomly polarized. Even double-heterojunction lasers often show low polarization when excited at high-power levels. It is desirable to have laser arrays which emit light that is strongly and uniformly polarized at all power levels. In order to achieve such polarization without sacrificing efficiency of the device or the compactness of the array, it is desirable to provide a cavity structure which allows discrimination of the TE set of modes with respect to the TM set without the use of an external cavity, and without any artifacts which interfere with the device performance. The cavity shown in Fig. 1 accomplishes this discrimination in the desired way.

Shown is a conventional cleaved array structure of GaAs 1, one end of which is antireflection coated 2 and onto which is placed crystal 3 of K(2)Pt(CN)(4)Br(.3) .3H(2)0. This crystal has a unique property, in that its reflectivity-for light polarized parallel to the Z-axis (where Z is the tetragonal chain axis) is about 80%, while for light polarized perpendicular to the axis, the reflectivity is about 5% at the GaAs wavelength. This is illustrated in Fig. 2. Crystals of this material grow naturally along the Z direction, so that when the long direction of the crystal is aligned with the junction plane, the gain of the TE mode overwhelms that of the TM mode.

Since junction lasers have been made wi...