US4991931A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of driving optical wavelength converter module
Assignee: Fujifilm Holdings Corp
•
Filing: 1990-01-26
•
Granted: 1991-02-12
•
Expires: 2010-01-26
Abstract
Abstract An optical wavelength converter module includes an optical wavelength converter device having a cladding and a waveguide which is disposed in the cladding and has a higher refractive index than the cladding, at least one of the cladding and the waveguide being made of a nonlinear optical material, whereby the wavelength of a fundamental which is propagating in the waveguide is converted. The optical wavelength converter module also includes a semiconductor laser for emitting a laser beam which is introduced as the fundamental into the waveguide. The semiconductor laser is driven with a pulsed drive current. The duration of the drive current pulses is made short enough to enable the semiconductor laser to produce a higher peak output power than when it is continuously driven, and it is made longer then a duration which falls within the range of pulse durations wherein the input coupling efficiency decreases as the pulse duration decreases and at which the wavelength conversion efficiency is equal to that which is achieved when the semiconductor laser is continuously driven.
Inventors
- 👤 Akinori Harada
- 👤 Yoji Okazaki
- 👤 Hiroshi Sunagawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 13:05
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/35; G02F1/37; G02F1/377; G02F1/383
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
197 words
A method of driving an optical wavelength converter module including an optical wavelength converter device having a cladding and a waveguide which is disposed in the cladding and has a higher refractive index than the cladding, at least one of the cladding and the waveguide being made of a nonlinear optical material, whereby the wavelength of a fundamental wave of a laser beam which is propagating in the waveguide is converted, the optical wavelength converter module also including a semiconductor laser for emitting said laser beam which is introduced as said fundamental wave of said laser beam into the waveguide, said method comprising the steps of: (i) driving the semiconductor laser with a pulsed drive current; and (ii) controlling a duration of said drive current pulses to enable a peak output power of the semiconductor laser to increase over that when the semiconductor laser is continuously driven, and controlling said duration of said drive current pulses to be longer than a duration within a range of pulse durations between which the input coupling efficiency decreases as the pulse duration decreases and the wavelength conversion efficiency is equal to that achieved when the semiconductor laser is continuously driven.
Claim 2
Independent Claim
197 words
A method of driving an optical wavelength converter module including an optical wavelength converter device having a cladding and a waveguide which is disposed in the cladding and has a higher refractive index than the cladding, at least one of the cladding and the waveguide being made of a nonlinear optical material, whereby the wavelength of a fundamental wave of a laser beam which is propagating in the waveguide is converted, the optical wavelength converter module also including a semiconductor laser for emitting said laser beam which is introduced as said fundamental wave of said laser beam into the waveguide, said method comprising the steps of: (i) driving the semiconductor laser with a pulsed drive current; and (ii) controlling a duration of said drive current pulses to enable a peak output power of the semiconductor laser to increase over that when the semiconductor laser is continuously driven, and controlling said duration of said drive current pulses to be longer than a duration within a range of pulse durations between which the input coupling efficiency decreases as the pulse duration decreases and the wavelength conversion efficiency is equal to that achieved when the semiconductor laser is continuously driven.
Claim 3
Dependent Claim
17 words
A method according to claim 1, wherein said duration of the drive current pulses is 1 μs.
Claim 4
Dependent Claim
15 words
A method according to claim 1, wherein said pulsed drive current is a rectangular wave.
Claim 5
Dependent Claim
15 words
A method according to claim 1, wherein said pulsed drive current is a square wave.
Claim 6
Independent Claim
197 words
An apparatus for driving an optical wavelength converter module including an optical wavelength converter device having a cladding and a waveguide which is disposed in the cladding and has a higher refractive index than the cladding, at least one of the cladding and the waveguide being made of a nonlinear optical material, whereby the wavelength of a fundamental wave of a laser beam which is propagating in the waveguide is converted, said optical wavelength converter module also including a semiconductor laser for emitting said laser beam which is introduced as said fundamental wave of said laser beam into the waveguide, said apparatus comprising: driving means for driving said semiconductor laser with a pulses drive current; and controlling means for controlling a duration of said drive current pulses to enable a peak output power of said semiconductor laser to increase over than when said semiconductor laser is continuously driven, and controlling said duration of drive current pulses to be longer than a duration within a range of pulse durations between which the input coupling efficiency decreases as the pulse duration decreases and a wavelength conversion efficiency is equal to that achieved when said semiconductor laser is continuously driven.
Claim 7
Independent Claim
197 words
An apparatus for driving an optical wavelength converter module including an optical wavelength converter device having a cladding and a waveguide which is disposed in the cladding and has a higher refractive index than the cladding, at least one of the cladding and the waveguide being made of a nonlinear optical material, whereby the wavelength of a fundamental wave of a laser beam which is propagating in the waveguide is converted, said optical wavelength converter module also including a semiconductor laser for emitting said laser beam which is introduced as said fundamental wave of said laser beam into the waveguide, said apparatus comprising: driving means for driving said semiconductor laser with a pulses drive current; and controlling means for controlling a duration of said drive current pulses to enable a peak output power of said semiconductor laser to increase over than when said semiconductor laser is continuously driven, and controlling said duration of drive current pulses to be longer than a duration within a range of pulse durations between which the input coupling efficiency decreases as the pulse duration decreases and a wavelength conversion efficiency is equal to that achieved when said semiconductor laser is continuously driven.
Claim 8
Dependent Claim
17 words
An apparatus according to claim 5, wherein said duration of said drive current pulses is one μs.
Claim 9
Dependent Claim
15 words
An apparatus according to claim 5, wherein said pulsed drive current is a rectangular wave.
Claim 10
Dependent Claim
15 words
An apparatus according to claim 5, wherein said pulsed drive current is a square wave.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-02-11 | 1994-08-13 | 1995-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-02-11 | 1998-08-13 | 1999-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-02-11 | 2002-08-13 | 2003-02-12 | $7700.00 | Window Closed / Lapsed |