EP0112188A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Light beam-splitter
Assignee: Crosfield Electronics Ltd
•
Filing: 1983-12-19
•
Granted: —
•
Expires: 2003-12-19
Abstract
Abstract Apparatus for splitting a light beam into a plurality of parallel beam of equal intensity comprises at least two blocks (32, 38, 42) of isotropic light-transmissive material, each block having one major face (30), on which the input beam is incident, coated to be partially transmissive, and an opposite parallel major face (34) silvered. The blocks are arranged in series so that the input beam, on reaching the first block, divides into a reflected part and a transmitted part which enters the block and, after internal reflection, provides an output beam (812) parallel to the reflected part of the first beam (B11), each subsequent block receiving all parallel beams from the preceding block or blocks. Optical means (26, 36, 40) may be provided in the beam path to ensure that each beam entering each block has equal S- and P-polarisation components.
Inventors
- 👤 John Edward Aughton
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 17:23
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/10; G02B27/106; G02B27/14; G02B27/144
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
172 words
Apparatus for producing a plurality of parallel light beams of substantially equal intensity from a single input beam, comprising a light source producing a collimated monochromatic light beam which is either totally non-polarised or is polarised with equal Sand P- polarisation components; and characterized by at least two blocks (32,38) of isotropic light-transmissive material having opposed parallel major faces, each block being silvered on one major face (34) and uniformly coated to be partially transmissive over the other major face (30); the blocks being positioned in series such that the light beam from the source in a plane normal to both faces strikes the partially-transmissive face of a first block and divides to provide, after internal reflection, a plurality of parallel output beams from the partially-transmissive face which then strike the next block in the series, each such subsequent block receiving the plurality of parallel beams and, by dividing and internal reflection, emitting a greater plurality of parallel beams, the total energy of which is substantially that of the original light beam.
Claim 2
Dependent Claim
172 words
Apparatus for producing a plurality of parallel light beams of substantially equal intensity from a single input beam, comprising a light source producing a collimated monochromatic light beam which is either totally non-polarised or is polarised with equal Sand P- polarisation components; and characterized by at least two blocks (32,38) of isotropic light-transmissive material having opposed parallel major faces, each block being silvered on one major face (34) and uniformly coated to be partially transmissive over the other major face (30); the blocks being positioned in series such that the light beam from the source in a plane normal to both faces strikes the partially-transmissive face of a first block and divides to provide, after internal reflection, a plurality of parallel output beams from the partially-transmissive face which then strike the next block in the series, each such subsequent block receiving the plurality of parallel beams and, by dividing and internal reflection, emitting a greater plurality of parallel beams, the total energy of which is substantially that of the original light beam.
Claim 3
Dependent Claim
91 words
Apparatus in accordance with claim 1, wherein the partially-transmissive coating (30) on the said other major face of each blocks is constructed such that, for the designed angle of incidence of the input beam or beams, one of the beams which is fully internally reflected in the silvered face (34) is totally transmitted through the opposite coated face (30), the apparatus further comprising optical means (36,40) positioned in the beam path between adjacent blocks in the series ensuring that each beam entering each block has equal S- and P- polarisation components.
Claim 4
Dependent Claim
73 words
Apparatus in accordance with claim 1, wherein each block provides two output beams (Bll, B12) for each input beam and an input beam with equal S- and P-polarisation components is split by the partially-transmissive surface (30) such that one component is partially reflected and the other component totally transmitted, the said other component finally emerging having undergone full internal reflection in the silvered face (34) followed by total transmission in the coated surface.
Claim 5
Dependent Claim
49 words
Apparatus in accordance with claim 1, wherein each block (46, 56) provides three output beans for each input beam and of the three emergent beams, one contains only one polarisation component, one contains the opposite polarisation component, and the middle beam contains an equal mixture of the two components.
Claim 6
Dependent Claim
24 words
Apparatus in accordance with any preceding claim, wherein a quarter-wavelength retarder (36) is placed in the light path between adjacent blocks in the series.
Claim 7
Dependent Claim
27 words
Apparatus in accordance with any of claims 1 to 4, wherein a 45° rotator (36) is placed in the light path between adjacent blocks in the series.
Claim 8
Dependent Claim
14 words
Apparatus in accordance with any preceding claim, wherein the light source is a laser.
Claim 9
Dependent Claim
44 words
Apparatus in accordance with any preceding claim, wherein further optical means (26) are positioned in the beam path between the light source and the first block of the series to ensure that the beam entering the block has equal S- and P- polarisation components.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.