Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
163 words
An optical switch having a substrate (21), and at least two optical waveguides (25-1, 25-2, 26-1, 26-2) on the substrate, the optical waveguides (25-1, 25-2, 26-1, 26-2) being long narrow layers intersecting each other at a predetermined angle such that they define a rhomboidal region (27-1, 27-2, 27-3, 27-4) at their intersection(s); characterised in that: there is at least one stripe layer (22, 23) having a predetermined width and thickness extending along the longer diagonal of the or each rhomboidal region (27-1, 27-2, 27-3, 27-4), the band gap of the or each stripe layer (22, 23) being equal or close to the wavelength of the light that the optical switch is to switch; the substrate (21), the optical waveguides (25-1, 25-2, 25-3, 25-4), and the or each stripe layer (22, 23) each being a compound semiconductor and all of the same compound semiconductor system; and the switch has means (24-1, 24-2, 24-3, 24-4, 31) for changing the carrier concentration of the stripe layer.
Claim 2
Dependent Claim
163 words
An optical switch having a substrate (21), and at least two optical waveguides (25-1, 25-2, 26-1, 26-2) on the substrate, the optical waveguides (25-1, 25-2, 26-1, 26-2) being long narrow layers intersecting each other at a predetermined angle such that they define a rhomboidal region (27-1, 27-2, 27-3, 27-4) at their intersection(s); characterised in that: there is at least one stripe layer (22, 23) having a predetermined width and thickness extending along the longer diagonal of the or each rhomboidal region (27-1, 27-2, 27-3, 27-4), the band gap of the or each stripe layer (22, 23) being equal or close to the wavelength of the light that the optical switch is to switch; the substrate (21), the optical waveguides (25-1, 25-2, 25-3, 25-4), and the or each stripe layer (22, 23) each being a compound semiconductor and all of the same compound semiconductor system; and the switch has means (24-1, 24-2, 24-3, 24-4, 31) for changing the carrier concentration of the stripe layer.
Claim 3
Dependent Claim
18 words
An optical switch according to claim 1, wherein the or each stripe layer includes electrodes for applying current.
Claim 4
Dependent Claim
30 words
An optical switch according to claim 2, wherein one of the electrodes has the same pattern as the stripe layer and is located directly or indirectly on the stripe layer.
Claim 5
Dependent Claim
27 words
An optical switch according to claim 3, wherein another electrode is located on the surface of the substrate opposite to that on which are the optical waveguides.
Claim 6
Dependent Claim
26 words
An optical switch according to any one of claims 1 to 4, wherein the or each stripe layer is an active layer of a P-N junction.
Claim 7
Dependent Claim
37 words
An optical switch according to any one of claims 1 to 5, wherein the compound semiconductor system is a group III - group V compound semiconductor system or a group II - group VI compound semiconductor system.
Claim 8
Dependent Claim
45 words
An optical switch according to any one of the preceding claims, wherein the compound semiconductor system is a GaAs system, an InP system, an InGaAsP system, a GaSb system, a GaAlAsSb system, a CdS system, a CdSe system, a ZnS system or a ZnSe system.
Claim 9
Dependent Claim
23 words
An optical switch according to claim 7, wherein the compound semiconductor system is a GaAs system, an InP system or an InGaAsP system.
Claim 10
Dependent Claim
41 words
An optical switch according to any one of the preceding claims having at least two optical waveguides which are parallel to each other and which have a predetermined interval therebetween, at least one other optical waveguide intersecting those two parallel waveguides.