Athermal optical assembly

Patent metadata

Field	Value
Publication number	US-11073677-B2
Application number	US-201615769916-A
Country	US
Kind code	B2
Filing date	Oct 21, 2016
Priority date	Oct 22, 2015
Publication date	Jul 27, 2021
Grant date	Jul 27, 2021

Abstract

This disclosure describes optical assemblies that generate output with substantial stability over a wide variation in temperature. The optical assemblies can be integrated, for example, as part of array generators arranged to project an array or other pattern of dots onto an object or projection plane.

First claim

What is claimed is:

1. A hybrid optical assembly comprising:
a first transmissive substrate;
a first aspherical lens on a first side of the first transmissive substrate;
a second hybrid diffractive/refractive lens on a second side of the first transmissive substrate;
a second transmissive substrate separated from the first transmissive substrate;
a third aspherical lens on a first side of the second transmissive substrate; and
a fourth aspherical lens on a second side of the second transmissive substrate;
wherein the third aspherical lens faces the second hybrid diffractive/refractive lens,
wherein the output of the hybrid optical assembly exhibits substantial stability over a temperature range of 20° C.-100° C., and
wherein the first and second transmissive substrates are separated from one another by a distance in a range of 4 mm-10 mm.

2. The hybrid optical assembly of claim 1 , further comprising an array of light emitting elements, wherein the light emitting elements are vertical cavity surface-emitting lasers (VCSELs).

3. The hybrid optical assembly according to claim 1 , wherein the first aspheric lens, the second hybrid diffractive/refractive lens, the third aspheric lens, and the fourth aspheric lens have focal-length-normalized diameters of 0.49, 0.49, 0.35, and 0.29, respectively.

4. The hybrid optical assembly according to claim 1 , wherein the first aspheric lens, the second hybrid diffractive/refractive lens, the third aspheric lens, and the fourth aspheric lens have focal-length-normalized thicknesses of 0.0044, 1.048, 0.067, and 0.067, respectively.

5. The hybrid optical assembly according to claim 1 , wherein the first aspheric lens has a focal-length-normalized curvature of 9.21, the second hybrid diffractive/refractive lens has a focal-length-normalized curvature of 2.85, the third aspheric lens has a focal-length-normalized curvature of 0.34, and the fourth aspheric lens has a focal-length-normalized curvature of 0.78.

6. The hybrid optical assembly according to claim 5 having an aspect ratio of 0.356.

7. The hybrid optical assembly according to claim 5 , the first, third and fourth aspherical lenses have the following coefficients, respectively:

1 st aspheric
3 rd aspheric
4 th aspheric

Coefficient (r)
lens
lens
lens

Fourth-order
−0.103
0.114
0.382

Sixth-order
0
2.4032
3.544

Eighth-order
0
−41.19
−62.281

Tenth-order
0
324.92
523.773

Twelfth-order
0
−1203.11
−1930.264

Fourteenth-order
0
1694.44
2348.243

and wherein the second hybrid diffractive/refractive lens has the following coefficients:

2 nd hybrid

diffractive/refractive

Coefficient (□)
lens

Aspheric Fourth-order
−0.115

Aspheric Sixth-order
−0.859

Aspheric Eighth-order
5.705

Aspheric Tenth-order
−17.849

Aspheric Twelfth-order
28.092

Aspheric Fourteenth-order
−17.554

Diffractive-phase Second-order
−525.287

Diffractive-phase Fourth-order
71.546

Diffractive-phase Sixth-order
−30.983.

8. The hybrid optical assembly according to claim 5 having an aspect ratio of 0.224.

9. The hybrid optical assembly according to claim 5 , wherein the first, third and fourth aspheric lenses have the following coefficients, respectively:

1 st aspheric
3 rd aspheric
4 th aspheric

Coefficient (r)
lens
lens
lens

Fourth-order
−0.026
0.028
0.095

Sixth-order
0
0.237
0.350

Eighth-order
0
−1.611
−2.436

Tenth-order
0
5.034
8.115

Twelfth-order
0
−7.384
−11.847

Fourteenth-order
0
4.119
5.709

Assignees

• Ams Sensors Singapore Pte Ltd

Inventors

• Engelhardt Kai
• Rossi Markus

Classifications

• G02B27/4205

  having a diffractive optical element [DOE] contributing to image formation, e.g. whereby modulation transfer function MTF or optical aberrations are relevant · CPC title

• G02B27/0056

  by using a diffractive optical element · CPC title

• G02B7/008 Primary

  with means for compensating for changes in temperature or for controlling the temperature; thermal stabilisation · CPC title

• G02B7/028 Primary

  with means for compensating for changes in temperature or for controlling the temperature; thermal stabilisation · CPC title

• G02B27/4233

  having a diffractive element [DOE] contributing to a non-imaging application (diffusers having a diffractive element G02B5/0252; filters having a diffractive element G02B5/203; systems for controlling the direction of light having diffractive elements G02B26/0808; scanning systems having diffractive elements G02B26/106; beam shaping systems using diffractive optical elements G02B27/0944; beam splitting or combining systems operating by diffraction G02B27/1086) · CPC title