Patent EP0377988A2 successfully refreshed from Google Patents.
EP0377988A2
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Wavelength converting optical device
Assignee: Toshiba Corp
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Filing: 1989-12-20
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Granted: —
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Expires: 2009-12-20
Abstract
Abstract A wavelength converting optical device includes an optical waveguide (10) which has a waveguide portion (11) and a cladding portion (12), at least one of which is formed of a nonlinear optical material. A fundamental wave, incident on the waveguide portion from an input end face (10b) of the waveguide, is converted into an optical second harmonic wave by Cerenkov radiation and is radiated into the cladding portion. The radiated second harmonic wave is output from an output end face (10a) of the waveguide. A reflecting film (14) is provided on the emerging end face of the waveguide. The reflecting film includes a high reflectivity with respect to the fundamental wave of a guide mode and a low reflectivity with respect to the optical second harmonic wave. A wave front converting element (31) is arranged to oppose the reflecting film. The converting element has a diffraction grating (32) for converting the second harmonic wave, emerging from the output end face of the waveguide, into a plane wave.
Inventors
- 👤 Genichi Intellectual Property Division Hatakoshi
- 👤 Masaki Intellectual Property Division Okajima
- 👤 Kazutaka Intellectual Property Division Terashima
- 👤 Yutaka Intellectual Property Division Uematsu
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 12:47
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/35; G02F1/37; G02F1/377; G02B; G02B27/00; G02B27/42; G02B27/4233; G02B6/00; G02B6/10; G02B6/12; G02B6/122; G02B6/124; G02B6/24; G02B6/26; G02B6/32; G02B6/34; G02B27/09; G02B27/0938; G02B27/0944; G02F1/372; G02F1/374; G02F1/383
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
160 words
A wavelength converting optical device comprising: optical waveguide means, including a waveguide portion and a cladding portion, at least one of which is formed of a nonlinear optical material, and input and output end faces, for converting a fundamental wave, incident on said waveguide portion from the input end face, into an optical second harmonic wave by Cerenkov radiation, radiating the optical second harmonic wave into said cladding portion, and outputting the radiated optical second harmonic wave from the output end face, said waveguide and cladding portions respectively having refractive indices for converting the incident fundamental wave and the second harmonic wave into a guided mode and a Cerenkov radiation beam, respectively; characterized in that: a reflecting film (14) is provided on said output end face (10a) of said optical waveguide means (10) and includes a high reflectivity with respect to the fundamental wave of the guided mode and a low reflectivity with respect to the optical second harmonic wave.
Claim 2
Dependent Claim
160 words
A wavelength converting optical device comprising: optical waveguide means, including a waveguide portion and a cladding portion, at least one of which is formed of a nonlinear optical material, and input and output end faces, for converting a fundamental wave, incident on said waveguide portion from the input end face, into an optical second harmonic wave by Cerenkov radiation, radiating the optical second harmonic wave into said cladding portion, and outputting the radiated optical second harmonic wave from the output end face, said waveguide and cladding portions respectively having refractive indices for converting the incident fundamental wave and the second harmonic wave into a guided mode and a Cerenkov radiation beam, respectively; characterized in that: a reflecting film (14) is provided on said output end face (10a) of said optical waveguide means (10) and includes a high reflectivity with respect to the fundamental wave of the guided mode and a low reflectivity with respect to the optical second harmonic wave.
Claim 3
Dependent Claim
46 words
A device according to claim 1, characterized in that said reflecting film (14) has a reflectivity of not less than 95% with respect to the fundamental wave of the guided mode and a reflectivity of not more than 5% with respect to the second harmonic wave.
Claim 4
Dependent Claim
46 words
A device according to claim 2, characterized in that said reflecting film (14) has a reflectivity of not less than 99% with respect to the fundamental wave of the guided mode and a reflectivity of not more than 2% with respect to the second harmonic wave.
Claim 5
Dependent Claim
72 words
A device according to claim 1, characterized by further comprising a second reflecting film (13), provided on said input end face (10b) of said optical waveguide means (10) and having a predetermined reflectivity with respect to the fundamental wave of the guided mode, for reflecting the fundamental wave of the guided mode, which is reflected by said first reflecting film (14) toward said input end face, toward said output end face (10a).
Claim 6
Dependent Claim
34 words
A device according to claim 4, characterized in that said second reflecting film (13) has a reflectivity within the range of 50 to 95% with respect to the fundamental wave of the guided mode.
Claim 7
Dependent Claim
36 words
A device according to claim 4, characterized in that said input and output end faces (10b and 10a) extend to be perpendicular to an optical axis of the fundamental wave input on said incidence end face.
Claim 8
Dependent Claim
42 words
A device according to claim 1, characterized in that said waveguide means (10) comprises a cylindrical waveguide portion (11) and a hollow cylindrical cladding portion (12) fixed to an outer surface of said waveguide portion and extending coaxially with said waveguide portion.
Claim 9
Dependent Claim
60 words
A device according to claim 1, characterized by further comprising a second reflecting film (13), provided on said input end face (10b) of said optical waveguide means (10) and having a high reflectivity with respect to the second harmonic wave, for reflecting the second harmonic wave, which is radiated toward said input end face, toward said output end face (10a).
Claim 10
Dependent Claim
60 words
A device according to claim 8, characterized in that said second reflecting film (13) has a predetermined reflectivity with respect to the fundamental wave of the guided mode so as to reflect the fundamental wave of the guided mode, which is reflected by said first reflecting film (14) toward said input end face (10b), toward said output end face (10a).
Claim 11
Dependent Claim
47 words
A device according to claim 9, characterized in that said second reflecting film (13) has a reflectivity of about 100% with respect to the second harmonic wave and a reflectivity within the range of 50 to 95% with respect to the fundamental wave of the guided mode.
Claim 12
Dependent Claim
14 words
A device according to claim 1, characterized by further comprising wave front converting means
Claim 13
Dependent Claim
40 words
(31), including a diffraction grating (32) arranged to oppose said reflecting film (14), for converting the second harmonic wave emerging from said output end face (10a) of said optical waveguide means (10) into one of plane, spherical and conical waves.
Claim 14
Dependent Claim
40 words
(31), including a diffraction grating (32) arranged to oppose said reflecting film (14), for converting the second harmonic wave emerging from said output end face (10a) of said optical waveguide means (10) into one of plane, spherical and conical waves.
Claim 15
Dependent Claim
159 words
A wavelength converting optical device comprising: optical waveguide means, including a waveguide portion and a cladding portion, at least one of which is formed of a nonlinear optical material, and input and output end faces, for converting a fundamental wave, incident on said waveguide portion from said input end face, into an optical second harmonic wave by Cerenkov radiation, radiating the optical second harmonic wave into said cladding portion, and outputting the radiated optical second harmonic wave from said output end face, said waveguide and cladding portions respectively having refractive indices for converting the incident fundamental wave and the second harmonic wave into a guided mode and a Cerenkov radiation beam, respectively; characterized in that: wave front converting means (31), having a diffraction grating (32) arranged to oppose said output end face (10a), for converting the second harmonic wave, emerging from said emerging end face of said optical waveguide means (10), into one of plane, spherical, and conical waves.
Claim 16
Dependent Claim
159 words
A wavelength converting optical device comprising: optical waveguide means, including a waveguide portion and a cladding portion, at least one of which is formed of a nonlinear optical material, and input and output end faces, for converting a fundamental wave, incident on said waveguide portion from said input end face, into an optical second harmonic wave by Cerenkov radiation, radiating the optical second harmonic wave into said cladding portion, and outputting the radiated optical second harmonic wave from said output end face, said waveguide and cladding portions respectively having refractive indices for converting the incident fundamental wave and the second harmonic wave into a guided mode and a Cerenkov radiation beam, respectively; characterized in that: wave front converting means (31), having a diffraction grating (32) arranged to oppose said output end face (10a), for converting the second harmonic wave, emerging from said emerging end face of said optical waveguide means (10), into one of plane, spherical, and conical waves.
Claim 17
Dependent Claim
58 words
A device according to claim 12, characterized in that said waveguide means (10) comprises a cylindrical waveguide portion (11) and a hollow cylindrical cladding portion (12) fixed to an outer surface of said waveguide portion and extending coaxially with said waveguide portion, and said diffraction grating (32) comprises a concentric pattern which is coaxial with said waveguide portion.
Claim 18
Dependent Claim
77 words
A device according to claim 12, characterized in that a grating pitch A of said diffraction grating (32) is set to satisfy A = M X 2 (n 2 sino,) where m is a positive integer, X 2 is the wavelength of the second harmonic wave, 9 c is the Cerenkov radiation angle in said cladding portion (12), and n 2 is the refractive index of said cladding portion with respect to the optical second harmonic wave.
Claim 19
Dependent Claim
26 words
A device according to claim 12, characterized in that said diffraction grating (32) is a diffraction grating of a blazed pattern having a sawtooth sectional shape.
Claim 20
Dependent Claim
44 words
A device according to claim 12, characterized in that said wave front converting means (31) comprises a substrate (34) having first and second converting surfaces (31 a and 31 b) opposing each other, said diffraction grating (32) being formed on said first converting surface.
Claim 21
Dependent Claim
36 words
A device according to claim 16, characterized in that said substrate (34) is arranged such that said first converting surface (31a) is in contact with said output end face (10a) of said optical waveguide means (10).
Claim 22
Dependent Claim
32 words
A device according to claim 16, characterized in that said wave surface converting means (31) comprises an antireflection film (35) formed on said second converting surface (31 b) of said substrate (34).
Claim 23
Dependent Claim
37 words
A device according to claim 16, characterized in that said wave front converting means (31) comprises a second diffraction grating (32b) having a concentric pattern formed on said second converting surface (31 b) of said substrate (34).
Claim 24
Dependent Claim
36 words
A device according to claim 16, characterized in that said wave front converting means (31) comprises a Fresnel lens type second diffraction grating (32b) formed on said second converting surface (31 b) of said substrate (34).
Claim 25
Dependent Claim
27 words
A device according to claim 16, characterized in that said second converting surface (31 b) of said substrate (34) has a conical shape or an aspherical shape.
Claim 26
Dependent Claim
35 words
A device according to claim 16, characterized in that said substrate (34) is arranged such that said second converting surface is in contact with said output end face (10a) of said optical waveguide means (10).
Claim 27
Dependent Claim
36 words
A device according to claim 12, characterized in that said input and output end faces (10b and 10a) of said optical waveguide means (10) extend to be perpendicular to an axis of said optical waveguide means.
Claim 28
Dependent Claim
55 words
A device according to claim 12, characterized by further comprising a first reflecting film (14) provided on said output end face (10a) of said optical waveguide means (10) and having a high reflectivity with respect to the fundamental wave of the guided mode and a low reflectivity with respect to the optical second harmonic wave.
Claim 29
Dependent Claim
69 words
A device according to claim 24, characterized by further comprising a second reflecting film (13), provided on said input end face (10b) of said optical waveguide means and having a predetermined reflectivity with respect to the fundamental wave of the guided mode, for reflecting the fundamental wave of the guided mode, which is reflected by said first reflecting film toward said input end face, toward said output end face.
Claim 30
Dependent Claim
48 words
A device according to claim 25, characterized in that said second reflecting film (13) has a predetermined high reflectivity with respect to the second harmonic wave so as to reflect the second harmonic wave, which is reflected radiated toward said input end face, toward said output end face.
Claim 31
Dependent Claim
35 words
A device according to claim 12, characterized in that said waveguide means (10) comprises a substrate constituting a substantially rectangular parallel-piped cladding portion (12), and said waveguide portion fixed to one surface of said substrate.
Claim 32
Dependent Claim
40 words
A device according to claim 27, characterized in that said diffraction grating (32) is constituted by part of an elliptic pattern and has a center located on an optical axis of the fundamental wave incident on said waveguide means (10).
Claim 33
Dependent Claim
62 words
A device according to claim 28, characterized in that major and minor axes of the elliptic pattern are set to have a ratio of no : n e , assuming that refractive indices of said clad portion (12) with respect to ordinary and extraordinary light-wave at a wavelength of the second harmonic wave are respectively represented by no and n e .
Claim 34
Dependent Claim
77 words
A device according to claim 27, characterized in that said diffraction grating (32) is constituted by part of a concentric pattern and has a center located on an optical axis of the fundamental wave incident on said waveguide means (10), at least one of said output end face (10a) of said waveguide means and said diffraction grating being inclined at a predetermined angle with respect to a plane perpendicular to the optical axis of the fundamental wave.
Claim 35
Dependent Claim
41 words
A device according to claim 30, characterized in that said output end face (10a) of said waveguide means (10) is located parallel to said plane, and said diffraction grating (32) is inclined at a predetermined angle with respect to said plane.
Claim 36
Dependent Claim
41 words
A device according to claim 30, characterized in that said output end face (10a) of said waveguide means (10) is inclined at a predetermined angle with respect to said plane, and said diffraction grating (32) is located parallel to the plane.
Claim 37
Dependent Claim
44 words
A device according to claim 30, characterized in that said output end face (10a) of said waveguide means (10) is inclined at a predetermined angle with respect to said plane, and said diffraction grating (32) is arranged in contact with said output end face.
References Cited (Backward Citations)
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