Surface emitting laser with monolithic integrated lens

Claim 2

In a monolithic lens-laser device, the element comprising: (a) a semiconductor substrate having first and second longitudinally extending opposed surfaces; (b) a strip of lasing medium extending in a generally longitudinal plane formed on said first surface for emitting light out one end thereof; (c) a lens having an optical axis and formed in said second surface for collimating light received from said lasing medium; and (d) a laser light reflective surface formed adjacent one end of said strip and located at the intersection of the optical axis of the lens and the plane of the lasing medium.

Claim 3

The device of claim 1 further including an additional light reflective surface formed in said second surface concentric with said lens to reflect radiated light back to said lasing.

Claim 4

The device of claim 2 wherein the additional light reflective surface comprises a spherical mirror coaxial to said lens to reflect light back to said lasing medium to support light oscillation.

Claim 5

The device of claim 2 wherein the additional light reflective surface is a spherical mirror located radially inwardly concentric with said lens to reflect light back to said lasing medium.

Claim 6

The device of claim 1 wherein the lens is covered by a reflective coating such that light collimated by the lens is reflected back toward the first surface and partly transmitted out the first surface and partly reflected back to the lasing medium to sustain laser oscillation.

Claim 7

The device of claim 1 wherein the laser light reflective surface is an internally reflective surface formed at an angle of about 45° to the plane of the strip.

Claim 8

The device of claim 1 wherein the laser light reflective surface is an internally reflective parabolic surface the focal point of which is located in the plane of the strip.

Claim 9

The device of claim 1 wherein the collimated light is directed toward an external cavity.

Claim 10

The device of claim 1 further including an additional partly light reflective surface formed in the path of said reflected light.

Claim 11

In an array of surface emitting laser devices wherein a plurality of laser structures are formed on a single substrate, each having lasing strips extending in the plane of the substrate, the improvement comprising: (a) a lens, having an optical axis, formed in the substrate on a surface oppositely adjacent each laser in a plane parallel to the plane of the substrate; and (b) a laser light reflective surface formed laterally adjacent each said laser for reflecting laser light from said laser toward said lens for collimation, said laser light reflective surface located at the intersection of the optical axis of the lens and the plane of the lasing strips.

Claim 12

In an array of surface emitting laser devices wherein a plurality of laser structures are formed on a single substrate, each having lasing strips extending in the plane of the substrate, the improvement comprising: (a) a lens, having an optical axis, formed in the substrate on a surface oppositely adjacent each laser in a plane parallel to the plane of the substrate; and (b) a laser light reflective surface formed laterally adjacent each said laser for reflecting laser light from said laser toward said lens for collimation, said laser light reflective surface located at the intersection of the optical axis of the lens and the plane of the lasing strips.

Claim 13

The array of claim 10 wherein the laser light reflective surface is a paraboloid.

Claim 14

The array of claim 10 wherein the laser light reflective surface is a 45° plane.

Claim 15

The array of claim 10 including a reflective mirror concentric to said lens.

Claim 16

The array of claim 10 wherein the lens is covered with a reflective material such that the collimated light is reflected back toward the substrate.

Claim 19

The method of claim 15 wherein a reflective spherical mirror is formed concentric with the lens.

Claim 20

The method of claim 16 wherein the lens is located radially central to the mirror.

Claim 21

The method of claim 15 wherein, after the lens is formed, the reflective surface is located at the intersection by projecting light through the lens to form an image on the second surface, which image is used as an alignment reference to locate the reflective surface.

Claim 22

The method of claim 15 wherein the laser structure is formed of a buffer layer, active layer and cladding layer formed on a substrate of thickness H and in which the reflective surface is formed by a thermal mass transport process, in which stepped grooves are formed in the laser structure with a sidewall of a first step located a lateral distance s 1 from the optical axis of the lens and the active layer is undercut from the end wall a distance "u", and the buffer layer thickness is B, and wherein the focal length of the lens "F" equals: H+B+s 1 +γ.

Claim 23

The method of claim 19 wherein prior to forming the lens, an alignment mark is formed in the substrate to a depth "v" and prior to forming the laser structure, the substrate surface on the laser side is removed to a depth "M" and wherein the focal length of the lens "F" equals H-γ-M+B+s 1 +γ.

Claim 24

The method of claim 15 wherein the lens profile "Z" equals: ##EQU3## wherein "n" is the refractive index of the substrate "τ" is the radial distance from the lens axis to a point on the profile. and "f" is the lens focal length.

Claim 25

The method of claim 15 wherein a spherical mirror is formed concentric to the lens and the radius of curvature of the spherical mirror "R" is: ##EQU4## wherein z' 3 is the lens thickness and τ' 3 is the axial radius of the lens.

Claim 26

In a monolithic mirror laser device, the improvement comprising: (a) a semiconductor substrate having first and second longitudinally extending opposed surfaces; (b) a strip of lasing medium for emitting light extending in a generally longitudinal plane formed over said first surface; (c) a mirror formed in said substrate adjacent said second surface for reflecting and collimating light received from said lasing medium; and (d) a laser light reflective surface formed adjacent one end of said strip and located at the intersection of the optical axis of the mirror and the plane of the lasing medium.

Claim 27

In a monolithic mirror laser device, the improvement comprising: (a) a semiconductor substrate having first and second longitudinally extending opposed surfaces; (b) a strip of lasing medium for emitting light extending in a generally longitudinal plane formed over said first surface; (c) a mirror formed in said substrate adjacent said second surface for reflecting and collimating light received from said lasing medium; and (d) a laser light reflective surface formed adjacent one end of said strip and located at the intersection of the optical axis of the mirror and the plane of the lasing medium.

Claim 28

In an array of surface emitting laser devices wherein a plurality of laser structures are formed on a single substrate, each having lasing strips extending in the plane of the substrate, the improvement comprising: (a) a mirror having an optical axis formed in the substrate on a surface oppositely adjacent each laser in a plane parallel to the plate of the substrate; and (b) a laser light reflective surface formed laterally adjacent each said laser for reflecting laser light from said laser toward said mirror for reflection, said laser light reflective surface located at the intersection of the optical axis of the mirror and the plane of the lasing strips.

Claim 29

In an array of surface emitting laser devices wherein a plurality of laser structures are formed on a single substrate, each having lasing strips extending in the plane of the substrate, the improvement comprising: (a) a mirror having an optical axis formed in the substrate on a surface oppositely adjacent each laser in a plane parallel to the plate of the substrate; and (b) a laser light reflective surface formed laterally adjacent each said laser for reflecting laser light from said laser toward said mirror for reflection, said laser light reflective surface located at the intersection of the optical axis of the mirror and the plane of the lasing strips.

Claim 30

The array of claim 24 wherein the laser light reflective surface is a paraboloid.

Claim 31

The array of claim 24 wherein the laser light reflective surface is a 45° plane.

Claim 32

In a monolithic lens-laser device, the improvement comprising: (a) a semiconductor substrate having first and second longitudinally extending opposed surfaces; (b) a strip of lasing medium for emitting light extending in a generally longitudinal plane formed over said first surface; (c) a lens formed in said substrate adjacent said second surface for collimating light received from said lasing medium; (d) a first laser light reflective surface formed adjacent one end of said strip and located at the intersection of the optical axis of the lens and the plane of the lasing medium; (e) a second light reflective mirror surface formed in said substrate concentric to said lens.

Claim 33

In a monolithic lens-laser device, the improvement comprising: (a) a semiconductor substrate having first and second longitudinally extending opposed surfaces; (b) a strip of lasing medium for emitting light extending in a generally longitudinal plane formed over said first surface; (c) a lens formed in said substrate adjacent said second surface for collimating light received from said lasing medium; (d) a first laser light reflective surface formed adjacent one end of said strip and located at the intersection of the optical axis of the lens and the plane of the lasing medium; (e) a second light reflective mirror surface formed in said substrate concentric to said lens.

Claim 34

The device of claim 27 wherein the second light reflective surface comprises a spherical mirror coaxial to said lens to reflect light back to said lasing medium to support light oscillation.

Claim 35

The device of claim 27 wherein the second light reflective surface is a spherical mirror located radially inwardly concentric with said lens to reflect light back to said lasing medium.

Claim 36

The device of claim 27 wherein the first laser light reflective surface is an internally reflective surface formed at an angle of about 45° to the plane of the strip.

Claim 37

The device of claim 27 wherein the first laser light reflective surface is an internally reflective parabolic surface the focal point of which is located in the plane of the strip.