US 12,066,609 B2
Multiple effective focal length (EFL) optical system
Matthew A. Sinclair, Stoneham, MA (US); and Juha-Pekka Laine, Boston, MA (US)
Assigned to The Charles Stark Draper Laboratory, Inc., Cambridge, MA (US)
Filed by The Charles Stark Draper Laboratory, Inc., Cambridge, MA (US)
Filed on Jun. 27, 2019, as Appl. No. 16/454,988.
Claims priority of provisional application 62/690,635, filed on Jun. 27, 2018.
Prior Publication US 2020/0004001 A1, Jan. 2, 2020
Int. Cl. G02B 17/08 (2006.01); G02B 17/06 (2006.01); G02B 27/14 (2006.01)
CPC G02B 17/0888 (2013.01) [G02B 17/061 (2013.01); G02B 17/0808 (2013.01); G02B 17/0856 (2013.01); G02B 27/141 (2013.01); G02B 27/142 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A multi-band telescope optical system, comprising:
a concave primary mirror assembly comprising a primary mirror, a first spacer on the primary mirror, a first dichroic coating on the first spacer, and a second dichroic coating on the first spacer to separately reflect different optical bands to create different focal lengths and/or fields of view for each of the different optical bands;
a curved secondary mirror that reflects light through an aperture in the primary mirror assembly; and
a detector system for separately detecting the different optical bands with different image sensors.