Patent ID: 11857158
Assignee: OLYMPUS CORPORATION
Field: Medical technology (Instruments)
Classification: CPC A  G | IPC A  G

Claim 3:
4. The optical system according to claim 3, wherein the following conditional expression (2) is satisfied:

0.8≤(np/Δn)/(d/lpc)≤4.4  (2)

where:
np denotes a refractive index for an e-line of a glass material used for the polarizing beam splitter,
Δn denotes the birefringence of the quarter-wave plate for the e-line (546.1 nm), provided that |0.01|<Δn,
d denotes the thickness of the quarter-wave plate, and
lpc denotes a thickness of an adhesive layer of an adhesive used on a surface of the polarizing beam splitter.