EP0361602A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
A light emitting device
Assignee: Philips Electronics UK Ltd
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Filing: 1989-09-22
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Granted: —
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Expires: 2009-09-22
Abstract
Abstract A light emitting device has an active layer (1) for generating light of a given wavelength (λ₁) in response to an external stimulus, and first and second cladding layers (2 and 3) bounding the active layer (1) for defining the active layer (1) as a waveguide for guiding light of the given wavelength (λ₁) along the active layer (1) to be emitted at an end face (1a) of the active layer. The active layer (1) and/or at least one of the cladding layers (3) is formed of an optically non-linear medium for causing light at half the given wavelength to be generated with light of the given wavelength, at least one cladding layer (3) having a periodic grating structure (4) having a period ∧ = (where λ₂ is half the given wavelength, m is the order of diffraction and n is the refractive index of the said one cladding layer) for phase-matching with light of half the given wavelength and being formed so as to be substantially transparent to light of half the given wavelength so as to enable light of half the given wavelength to emerge via the periodic grating (4) normally of the active layer (1).
Inventors
- 👤 Peter James Chy-Yn-Meneth Dobson
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 17:08
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/10; H01S5/12; H01S5/18; H01S5/185; H01S5/187; H01S5/04; H01S5/041; H01S5/06; H01S5/0604; H01S5/0605; H01S5/30; H01S5/32; H01S5/3211
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
183 words
A light emitting device comprising an active layer for generating light of a given wavelength in response to an external stimulus, and first and second cladding layers bounding the active layer for defining the active layer as a waveguide for guiding light of the given wavelength along the active layer to be emitted at an end face of the active layer, the active layer and/or at least one cladding layer comprising an optically non-linear medium for causing light at half the given wavelength to be generated with light of the given wavelength, characterised in that the said at least one cladding layer has a periodic grating structure having a period ∧ = (where λ₂ is half the given wavelength, m is the order of diffraction and n is the refractive index of the said one cladding layer) for phase-matching with light of half the given wavelength and is formed so as to be substantially transparent to light of half the given wavelength so as to enable light of half the given wavelength to emerge via the periodic grating normally of the active layer.
Claim 2
Dependent Claim
183 words
A light emitting device comprising an active layer for generating light of a given wavelength in response to an external stimulus, and first and second cladding layers bounding the active layer for defining the active layer as a waveguide for guiding light of the given wavelength along the active layer to be emitted at an end face of the active layer, the active layer and/or at least one cladding layer comprising an optically non-linear medium for causing light at half the given wavelength to be generated with light of the given wavelength, characterised in that the said at least one cladding layer has a periodic grating structure having a period ∧ = (where λ₂ is half the given wavelength, m is the order of diffraction and n is the refractive index of the said one cladding layer) for phase-matching with light of half the given wavelength and is formed so as to be substantially transparent to light of half the given wavelength so as to enable light of half the given wavelength to emerge via the periodic grating normally of the active layer.
Claim 3
Dependent Claim
47 words
A device according to Claim 1, further characterised in that the said one cladding layer has a free surface defining alternate crests and troughs and the said one cladding layer is sufficiently thin at the troughs to be substantially transparent to light of half the given wavelength.
Claim 4
Dependent Claim
20 words
A device according to Claim 2, further characterised in that the two cladding layers are formed of the same material.
Claim 5
Dependent Claim
47 words
A device according to Claim 1, further characterised in that the said one cladding layer is formed of a material transparent to light of half the given wavelength and the periodic grating is formed at the interface between the said one cladding layer and the active layer.
Claim 6
Dependent Claim
26 words
A device according to Claim 1, 2, 3 or 4, further characterised in that the active layer and the other cladding layer comprise III-V semiconductor material.
Claim 7
Dependent Claim
32 words
A device according to Claim 4, further characterised in that the active layer and the other cladding layer comprise III-V semiconductor material whilst the said one cladding layer comprises II-VI semiconductor material.
Claim 8
Dependent Claim
17 words
A device according to Claim 6, further characterised in that the II-VI semiconductor material comprises zinc sulphide.
Claim 9
Dependent Claim
28 words
a device according to Claim 5, 6 or 7, further characterised in that the active layer comprises gallium arsenide and the other cladding layer comprises aluminium gallium arsenide.
Claim 10
Independent Claim
58 words
A device according to any one of the preceding claims, further characterised in that the first and second cladding layers are semiconductor layers doped with impurities of opposite conductivity type and electrically conductive contacts are provided on the first and second cladding layers for enabling a voltage to be applied across the device to provide the external stimulus.
Claim 11
Dependent Claim
57 words
A device according to Claim 9, further characterised in that the electrically conductive contact provided on the said one cladding layer is such that, at half the given wavelength, the real part of the dielectric constant of the said one cladding layer is of equal magnitude but opposite sign to that of the said one cladding layer.
References Cited (Backward Citations)
No citation records indexed.
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