Browse Prior Art Database

A Low Cost, High Efficiency Laser Diode Receptacle for Fiber Optic Communication Systems

IP.com Disclosure Number: IPCOM000041084D
Original Publication Date: 1987-Jul-01
Included in the Prior Art Database: 2005-Feb-02
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Block, TR: AUTHOR [+4]

Abstract

The receptacle uses a laser diode 1A as the source and a gradient index lens 2, with lens 2 being located such that a distance L1 is maintained from the exit surface of the lens 2 to the entrance of the optical fiber 3.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 90% of the total text.

Page 1 of 1

A Low Cost, High Efficiency Laser Diode Receptacle for Fiber Optic Communication Systems

The receptacle uses a laser diode 1A as the source and a gradient index lens 2, with lens 2 being located such that a distance L1 is maintained from the exit surface of the lens 2 to the entrance of the optical fiber 3.

Laser 1 is a standard "G" package laser having a semiconductor laser chip 1A and is used as the source. The widely diverging beam from the laser is collected and brought to a focus by the gradient index lens 2. These lenses are in high volume production for the photocopying industry and are available at very low prices. The lens brings the energy to focus at a distance L1 from its exit surface where the optical fiber 3 is located.

The lens "power" or pitch and the laser to lens distance determine the distance L1. The distance L1 must be short enough so as to not overmagnify the laser near field image and yet not so small so as to overfill the numerical aperture of the fiber. The lens placement should be measured relative to the flange of the laser package, and not placed against the laser's window glass. Positioning the lens in this manner will result in less variation in the longitudinal ray crossing position due to package tolerances.

Laser 1 is a relatively low cost light emitting source and is presently in volume production for the compact audio disc (CD) market. This receptacle enables the user to take advantage of the high coupling efficiency and increas...