To provide an optical element which reduces the number of components and suppresses manufacturing costs from being increased or convergence tolerance from being deteriorated.
In an optical element, two light beams (A and B) are inputted to a birefringence material 10, four output light beams comprised of normal light beams (a1 and b1) and abnormal light beams (a2 and b2) corresponding to the input light beams are outputted, and the output light beams are made incident to a light-receiving element 40 while reducing a beam diameter and narrowing a beam interval. In the optical element, in an output terminal of the birefringence material 10, optical path conversion means 20 is disposed which converts an optical path in such a manner that the four output light beams (a1, a2, b1 and b2) cross approximately at one point (chain line D) and between the crossing point and the light-receiving element 40, convergence means 30 is provided which reduces the beam diameter of each output light beam.
HAYAMI YUJI
KATAOKA TOSHIO
OIKAWA YOICHI
SHIGA NORIYASU
OTA KAZUYA
TRIMATIZ:KK
Junko Sugimura