Multiple Effective Focal Length (EFL) Optical System

Patent metadata

Field	Value
Publication number	US-2024369814-A1
Application number	US-202418772353-A
Country	US
Kind code	A1
Filing date	Jul 15, 2024
Priority date	Jun 27, 2018
Publication date	Nov 7, 2024
Grant date	—

Abstract

A multi-band/multi-polarization reflective or catadioptric optical system yields differing effective focal lengths (EFLs) per band/polarization. This approach could be used to create an imaging system, for example. In such case, a sensor (imager, spectrometer, diode, etc.) is located at the one or more focal planes. On the other hand, it could also be used to create a projecting system or hybrid projecting and imaging system by locating an emitter such as an LED, laser, etc.) at the image or focal plane. The system employs polarizers and/or dichroic coatings nano patterns to create different focal lengths and/or fields of view using the same mirrors and/or lenses by, for example, including at least one dichroic coating optically in front of at least one additional mirror to separately reflect the different bands or polarizations.

First claim

What is claimed is:

1 . A multi-band optical system having a plurality of mirrors and/or lenses and a plurality of polarizers and/or dichroic coatings and/or patterned optical surfaces, in which the optical system uses the polarizers and/or dichroic coatings and/or patterned optical surfaces to effectuate different focal lengths and/or fields of view using the same mirrors and/or lenses.

2 . The optical system of claim 1 , wherein the optical system is an imaging system that images different optical bands on different image sensors.

3 . The optical system of claim 1 , wherein the optical system is at least partially a projection system that projects light using the mirrors and/or lenses.

4 . The optical system of claim 1 , further comprising one or more mirror assemblies, each including at least one dichroic coating optically in front of at least one additional mirror to separately reflect the different bands.

5 . The optical system of claim 4 , further comprising two mirror assemblies in a Cassegrain and/or Gregorian configuration.

6 . The optical system of claim 1 , further comprising a series of lenses including a first dichroic coating and an annular shaped dichroic coating that reflect one band within the series of lenses while transmitting another band though the lenses.

7 . The optical system of claim 1 , wherein the optical system has a segmented-circular profile.

8 . The optical system of claim 7 , wherein the patterned optical surfaces are nano-patterns etched into the mirrors or lenses.

9 . A compound lens optical system, comprising:
a series of lens for transmitting light; and a first dichroic or polarizing mirror coating or patterned optical surface and an annular shaped dichroic or polarizing mirror coating or patterned optical surface that reflect one band or polarization within the series of lenses.

10 . The optical system of claim 9 , wherein the first coating and the annular shaped coating are dichroic coatings.

11 . The optical system of claim 9 , wherein at least one of the first coating and the annular shaped coating coatings is located within a lens of the series of lenses.

12 . The optical system of claim 9 , wherein at least one of the first coating and the annular shaped coating is located on a surface of a lens of the series of lenses.

13 . A mirror assembly, comprising:
a lens substrate; a dichroic or polarizing mirror coating on a front surface of the lens substrate for reflecting light of a first spectral band or polarization; and mirror coating on a back surface of the lens substrate.

14 . The mirror assembly of claim 13 , wherein the lens substrate is a convexo-concave lens.

15 . The mirror assembly of claim 13 , wherein the lens substrate is a biconvex lens.

16 . The mirror assembly of claim 13 , wherein the mirror coating is bonded to the lens substrate.

17 . The mirror assembly of claim 13 , wherein the mirror coating is deposited to the lens substrate.

Assignees

• Charles Stark Draper Laboratory Inc

Inventors

• Sinclair Matthew A
• Laine Juha-Pekka

Classifications

• G02B27/142

  Coating structures, e.g. thin films multilayers · CPC title

• G02B27/141

  using dichroic mirrors · CPC title

• G02B17/061

  on-axis systems with at least one of the mirrors having a central aperture · CPC title

• G02B17/0808 Primary

  on-axis systems with at least one of the mirrors having a central aperture · CPC title

• G02B17/0856

  comprising a refractive element with a reflective surface, the reflection taking place inside the element, e.g. Mangin mirrors · CPC title