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US 2003/0076598 A1Published application
Optical coupling system and optical device using the same
AssigneeNippon Sheet Glass Co., Ltd.
InventorsShigeo Kittaka, Hideshi Nagata, Tatsuhiro Nakazawa, Yasuji Sasaki, Minoru Taniyama
Life of this patent
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Abstract
Two lenses are used for forming a collimator parallel pair, in which the distance between the two lenses is substantially made coincident with the maximum distance allowing beam waists to be formed at equal distances from the two lenses respectively.
Claims17
An optical coupling system comprising:
- a first lens having an incident surface disposed in a certain direction and having a positive refractive power, by said first lens, Gaussian beam-like luminous flux incident on said incident surface from a light source being converted into approximately parallel luminous flux;
- and
- a second lens having the same refractive power as that of said first lens but having an incident surface and exit surface disposed in a reverse direction, by said second lens, said approximately parallel luminous flux incident on said incident surface of said second lens being converted into converged luminous flux, said converged luminous flux being incident on a light-receiving unit;
- wherein a distance 2L between the two lenses is selected to be in a range given by an expression:
- 1.8Lmax≦2L≦2Lmax
- in which 2Lmax is a maximum distance allowing beam waists to be formed at equal distances from the two lenses respectively.
3 more elements
An optical coupling system comprising:
- a lens having a positive refractive power, by said lens, Gaussian beam-like luminous flux emitted from a light source being converted into approximately parallel luminous flux;
- and
- a reflection surface disposed at the rear of said lens so that said approximately parallel luminous flux is reflected by said reflection surface to return to said lens, said returning luminous flux being converted by said lens into converged luminous flux which is incident on a light-receiving unit disposed in said light source and its vicinity;
- wherein a distance L between said lens and said reflection surface is selected to be in a range given by an expression:
- 0.9Lmax≦L≦Lmax
- in which Lmax is a maximum distance allowing said lens to form a beam waist.
3 more elements
Dependencies are inferred from the claim text.