Browse Prior Art Database

Semiconductor Laser

IP.com Disclosure Number: IPCOM000105302D
Original Publication Date: 1993-Jul-01
Included in the Prior Art Database: 2005-Mar-19

Publishing Venue

IBM

Related People

Fukuzawa, T: AUTHOR

Abstract

The following is disclosed: 1. A surface-emitting semiconductor laser that has a resonant cavity for laser oscillation and whose direction is perpendicular to the semiconductor substrate, said laser comprising two laser mirrors, at least one of which is made up of multiple paired layers of semiconductors, one layer in each pair being ZnSe. 2. The semiconductor laser of (1), wherein ZnSe is replaced by CaSrF&sub2.. 3. The semiconductor laser of (1), wherein the multi-layered mirror is made up of layers of ZnSe and GaAs. 4. The semiconductor laser of (1), wherein the multi-layered mirror is made up of layers of ZnSe and GaAlAs.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 21% of the total text.

Semiconductor Laser

      The following is disclosed:

1.  A surface-emitting semiconductor laser that has a resonant cavity
    for laser oscillation and whose direction is perpendicular to the
    semiconductor substrate, said laser comprising two laser mirrors,
    at least one of which is made up of multiple paired layers of
    semiconductors, one layer in each pair being ZnSe.
2.  The semiconductor laser of (1), wherein ZnSe is replaced by
    CaSrF&sub2..
3.  The semiconductor laser of (1), wherein the multi-layered mirror
    is made up of layers of
     ZnSe and GaAs.
4.  The semiconductor laser of (1), wherein the multi-layered mirror
    is made up of layers of ZnSe and GaAlAs.

Field of Invention - The present invention relates to a
vertical-cavity surface-emitting laser that can be used in optical
parallel information processing, optical interconnection, and many
other optoelectronic fields.

Background - Semiconductor lasers are widely used in the fields of
optical communication, optical disks, laser beam printers and so on.
Almost all the one used in applications have the structure shown in
Fig. 1.  Here, a semiconductor laser has a semiconductor double
hetero-structure 2, 3, and 4, and the layers are parallel to the
semiconductor substrate 1.  The laser light is confined by the double
hetero-structure, and laser the mirrors are perpendicular to the
substrate.  In this case, laser light 8 comes from the edge of the
semiconductor's cleaved facets 7 and 7'.  Consequently, this type of
semiconductor laser is called an edge-emitting laser.  Therefore,
laser oscillation is possible only after the cleaving process has
been used to make laser mirrors.  After this process, a semiconductor
wafer is divided into small laser chips, whose dimensions are
typically 0.2 mm x 0.3 mm.  The handling and evaluation of each laser
are very elaborate procedures.

      On the other hand, if the laser cavity is perpendicular to the
semiconductor substrate, as shown in Fig. 2, laser light 20 comes
from the laser surface 17.  Laser oscillation is possible before the
scribing and cleaving processes.  This means that wafer-level
handling can be used to evaluate the laser optical characterization
and also the electrical behavior.

      A large-scale two-dimensional integration of a surface-emitting
laser is also possible.  Such a laser array has quite a strong
potential for use in parallel optical data processing and optical
interconnection.

      The first laser oscillation of a surface-emitting laser at
liquid nitrogen temperature was reported by Prof.  Iga of the Tokyo
Institute of Technology [1].

      In 1989, the surface emitting laser oscillation at room
temperature was reported[2], and a laser threshold current as low as
1 mA is realized[3].  These achievements resulted from improvements
in laser cavity mirrors.  Mean power reflectivity R is defined as the
root of the product of R&sub1...