A 1.3μm connectorized laser package has been proposed which uses a low-cost Compact Disk package coupled to single-mode fiber using two graded-index lenses. The threaded laser module consists of the Compact Disk package mounted directly behind a graded-index lens. This lens serves to collimate the laser radiation. The laser module can then be connected to single-mode fiber by means of a single-mode connector with a second graded-index lens permanently attached to the connector end. The second lens serves to focus the laser radiation onto the fiber core. Alignment sensitivity at the lens-lens interface is reduced, resulting in a highly tolerant connection. The decrease in lateral alignment sensitivity is achieved by trading it off for some unneeded angular tolerance, and some loss of coupling efficiency. In this paper, we will present results of calculations showing how to determine given coupling efficiency/sensitivity trade-offs by making appropriate lens selection. Graded-index lenses are identified and selected on the basis of pitch, which is simply proportional to the length of the lens. In addition, we note that the effective angular alignment at the lens-lens interface can be quite sensitive, depending on the fiber connector used. We propose a means of avoiding this difficulty, using a modified biconic connector design.
[1]
B. Deloach,et al.
Alignment of Gaussian beams.
,
1984,
Applied optics.
[2]
L. A. Reith,et al.
Design parameters for a 1.3μm connectorised low-cost laser package for subscriber loop using graded-index lenses
,
1987
.
[3]
R. L. Gallawa,et al.
Optoelectronic Materials, Devices, Packaging, and Interconnects II
,
1989
.
[4]
P. W. Shumate,et al.
Laser coupling to single-mode fibre using graded-index lenses and compact disc 1.3 μm laser package
,
1986
.
[5]
Herwig Kogelnik,et al.
Laser beams and resonators
,
1966
.