Patent ID: 8141785

Claim:
An optical delay module for lengthening the propagation path of a light beam, comprising: a first mirror and a second mirror, said first and second mirrors being situated opposite one another at a mirror distance from one another; a coupling-in area for coupling said light beam into a space between said first and second mirrors, and a coupling-out area for coupling the light beam out of said space between said first and second mirrors, said propagation path of said light beam between said coupling-in area and said coupling-out area corresponding at least approximately to quadruple said mirror distance; at least one optical arrangement arranged between said first and second mirrors, said optical arrangement being arranged to transfer said light beam without masking out of beam parts between said first and second mirrors in such a way that said propagation path of said light beam between said coupling-in area and said coupling-out area corresponds approximately to 2N times said mirror distance, where N is an integer >2.