US5003550A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Integrated laser-amplifier with steerable beam
Assignee: SDL Inc
•
Filing: 1990-03-09
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Granted: 1991-03-26
•
Expires: 2010-03-09
Abstract
Abstract A monolithic integrated master oscillator power amplifier (MOPA) device including a single mode diode laser with distributed Bragg reflectors, an amplifier in tandem with the laser, lateral phase controllers and a detuned second order grating surface output coupler, all on a common substrate. The amplifier is a flared waveguide in one embodiment, and a branching network of single mode waveguides followed by an array of single mode gain waveguides in another embodiment. The diode laser is tunable by means of a separate tuning current applied to the rear Bragg reflector. Tuning the laser wavelength provides, in conjunction with the output coupler, a longitudinal steering of the output beam. The lateral phase controllers are an array of separately addressable electrodes that adjust the optical path length to compensate for phase variation in the amplifiers and also to provide lateral steering of the output beam. An additional embodiment includes a chain of amplifiers and grating output couplers for providing multiple output beams.
Inventors
- 👤 David F. Welch
- 👤 Robert G. Waarts
- 👤 David G. Mehuys
- 👤 Richard R. Craig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:55
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/40; H01S5/42; H01S5/50; H01S5/02; H01S5/026; H01S5/06; H01S5/062; H01S5/06233; H01S5/06243; H01S5/0625; H01S5/06255; H01S5/06256; H01S5/10; H01S5/1053; H01S5/1064; H01S5/12; H01S5/125; H01S5/18; H01S5/185; H01S5/187; H01S5/4025; H01S5/4031; H01S5/4068; H01S5/4075
Claims Analysis
Total Claims: 47
Claim 1
Independent Claim
94 words
A master oscillator power amplifier device comprising a semiconductor laser formed on a substrate for lightwave generation, electrical means for exciting said laser, amplifier means, formed on said substrate and positioned so as to accept light from said laser, for providing lightwave amplification, electrical means for exciting said amplifier means, a detuned grating output coupler disposed to receive said amplified lightwaves, said grating output coupler having a period which minimizes optical feedback into the amplifier means to the extent that said amplifier means does not oscillate, thereby producing a coherent single mode output beam.
Claim 2
Dependent Claim
94 words
A master oscillator power amplifier device comprising a semiconductor laser formed on a substrate for lightwave generation, electrical means for exciting said laser, amplifier means, formed on said substrate and positioned so as to accept light from said laser, for providing lightwave amplification, electrical means for exciting said amplifier means, a detuned grating output coupler disposed to receive said amplified lightwaves, said grating output coupler having a period which minimizes optical feedback into the amplifier means to the extent that said amplifier means does not oscillate, thereby producing a coherent single mode output beam.
Claim 3
Dependent Claim
17 words
The device of claim 1 wherein said laser is an electrically wavelength tunable distributed Bragg reflector laser.
Claim 4
Dependent Claim
16 words
The device of claim 1 wherein said laser is an electrically wavelength tunable distributed feedback laser.
Claim 5
Dependent Claim
14 words
The device of claim 1 wherein said laser includes a pair of grating reflectors.
Claim 6
Dependent Claim
12 words
The device of claim 1 wherein said laser includes a mirror reflector.
Claim 7
Dependent Claim
15 words
The device of claim 1 wherein said laser includes one grating reflector and one mirror.
Claim 8
Dependent Claim
13 words
The device of claim 1 wherein said laser is a single mode laser.
Claim 9
Dependent Claim
12 words
The device of claim 1 wherein amplifier means comprises an amplifier region.
Claim 10
Dependent Claim
13 words
The device of claim 1 wherein said amplifier means comprises multiple amplifier regions.
Claim 11
Dependent Claim
14 words
The device of claim 1 wherein said amplifier means supports only single mode propagation.
Claim 12
Dependent Claim
18 words
The device of claim 1 wherein said laser has an InGaAs active region and said substrate is GaAs.
Claim 13
Dependent Claim
81 words
The device of claim 1 further comprising alternating additional amplifier means for providing light amplification and grating output coupler, said amplifier means and grating output couplers being disposed on said substrate in tandem after the first grating output coupler, each of said amplifier means having electrical means for exciting said amplifier means, each of said grating output couplers providing an output beam and having a period which is different from any Bragg reflector period providing significant reflection back toward said laser.
Claim 14
Dependent Claim
109 words
A master oscillator power amplifier device comprising a semiconductor laser formed on a substrate for lightwave generation, electrical means for exciting said laser, amplifier means, formed on said substrate and positioned so as to accept light from said laser, for providing lightwave amplification, electrical means for exciting said amplifier means, a grating output coupler disposed to receive said amplified lightwaves, said grating output coupler having a period which is different from any Bragg reflector period providing a significant reflection back to said laser, thereby producing a coherent single mode output beam, and means for tuning a wavelength of light from said laser, whereby said output beam is spatially steered.
Claim 15
Dependent Claim
109 words
A master oscillator power amplifier device comprising a semiconductor laser formed on a substrate for lightwave generation, electrical means for exciting said laser, amplifier means, formed on said substrate and positioned so as to accept light from said laser, for providing lightwave amplification, electrical means for exciting said amplifier means, a grating output coupler disposed to receive said amplified lightwaves, said grating output coupler having a period which is different from any Bragg reflector period providing a significant reflection back to said laser, thereby producing a coherent single mode output beam, and means for tuning a wavelength of light from said laser, whereby said output beam is spatially steered.
Claim 16
Dependent Claim
18 words
The device of claim 13 wherein said tuning means comprises means for varying a temperature of said laser.
Claim 17
Dependent Claim
20 words
The device of claim 13 wherein said tuning means comprises means for varying an electrical current supplied to said laser.
Claim 18
Dependent Claim
148 words
A master oscillator power amplifier device comprising, a semiconductor diode laser having at least one active region for lightwave generation, electrical pump means for injecting current into said active region to generate said lightwaves, waveguide means for propagation of said lightwaves, and reflector means for providing feedback of said lightwaves, amplifier means disposed in tandem with said laser for providing an optical power gain to said lightwaves, said amplifier means including an active region, a waveguide optically coupled to said laser to receive said lightwaves, and means for pumping said active region to amplify said lightwaves, said amplifier means integral with said laser on a common monolithic substrate, and a grating output coupler disposed to receive said amplified lightwaves, said coupler having a grating period which is different from any Bragg reflector period providing significant reflection back to said laser, thereby producing a coherent single mode output beam.
Claim 19
Dependent Claim
148 words
A master oscillator power amplifier device comprising, a semiconductor diode laser having at least one active region for lightwave generation, electrical pump means for injecting current into said active region to generate said lightwaves, waveguide means for propagation of said lightwaves, and reflector means for providing feedback of said lightwaves, amplifier means disposed in tandem with said laser for providing an optical power gain to said lightwaves, said amplifier means including an active region, a waveguide optically coupled to said laser to receive said lightwaves, and means for pumping said active region to amplify said lightwaves, said amplifier means integral with said laser on a common monolithic substrate, and a grating output coupler disposed to receive said amplified lightwaves, said coupler having a grating period which is different from any Bragg reflector period providing significant reflection back to said laser, thereby producing a coherent single mode output beam.
Claim 20
Dependent Claim
31 words
The device of claim 16 further comprising, means disposed between said amplifier and said output coupler for adjusting the relative phase between laterally adjacent portions of said lightwaves from said amplifier.
Claim 21
Dependent Claim
51 words
The device of claim 16 wherein said waveguide means of said laser and said waveguide of said amplifier means include waveguide regions proximate to said respective active regions of said laser and said amplifier means, said waveguide region of said amplifier means being optically coupled at one end to said laser.
Claim 22
Dependent Claim
23 words
The device of claim 16 wherein said waveguide means of said laser supports only a single spatial mode of propagation of said lightwaves.
Claim 23
Dependent Claim
18 words
The device of claim 16 wherein said reflector means of said laser includes at least one Bragg reflector.
Claim 24
Dependent Claim
29 words
The device of claim 16 wherein said laser has a tuning means for injecting current at said Bragg reflector means so as to shift a wavelength of said lightwaves.
Claim 25
Dependent Claim
20 words
The device of claim 16 wherein said waveguide of said amplifier means has an increasing width away from said laser.
Claim 26
Dependent Claim
19 words
The device of claim 16 wherein said active regions of said laser and said amplifier include InGaAs strain layers.
Claim 27
Dependent Claim
14 words
The device of claim 16 wherein a light absorbing region follows said output coupler.
Claim 28
Dependent Claim
127 words
The device of claim 16 further comprising additional amplifier means for providing an optical power gain to said lightwaves and additional grating output couplers disposed on said common monolithic substrate, said additional amplifier means and additional grating means alternating with one another in tandem following the first grating output coupler, each of said amplifier means including an active region, a waveguide optically coupled to a preceding grating output coupler to receive said lightwaves and means for pumping said active region to amplify said lightwaves, each of said grating output couplers being disposed amplified lightwaves from a preceding amplifier means and having a grating period which is different from any Bragg reflector period providing significant reflection back toward said laser, each grating output coupler producing an output beam.
Claim 29
Dependent Claim
47 words
The device of claim 16 wherein said amplifier means has a branching waveguide network coupled to an end of said laser by a linear array of amplifier sections, said waveguide network having a broad area current supply electrode, said linear array having plural independently addressable current electrodes.
Claim 30
Dependent Claim
163 words
A master oscillator power amplifier device comprising, a semiconductor diode laser formed on a substrate, the laser having a waveguide supporting propagation of only a single spatial mode, the laser also having a pair of grating reflectors, a rear one of said grating reflectors being characterized by strong frequency selectivity, said laser being wavelength tunable with a variable tuning current injected through said rear reflector, a flared index guided waveguide optically coupled to an output of said laser waveguide, said waveguide widening from input to output on an angle less than a divergence angle of light from said laser, said flared waveguide having a broad area electrical contact disposed proximate thereto so as to supply an amplification current thereto, said flared waveguide formed on said substrate monolithically with said laser, and a second-order grating disposed to receive amplified light from said flared waveguide, said grating having a period different from that of said grating reflectors, thereby producing a coherent single mode output beam.
Claim 31
Dependent Claim
163 words
A master oscillator power amplifier device comprising, a semiconductor diode laser formed on a substrate, the laser having a waveguide supporting propagation of only a single spatial mode, the laser also having a pair of grating reflectors, a rear one of said grating reflectors being characterized by strong frequency selectivity, said laser being wavelength tunable with a variable tuning current injected through said rear reflector, a flared index guided waveguide optically coupled to an output of said laser waveguide, said waveguide widening from input to output on an angle less than a divergence angle of light from said laser, said flared waveguide having a broad area electrical contact disposed proximate thereto so as to supply an amplification current thereto, said flared waveguide formed on said substrate monolithically with said laser, and a second-order grating disposed to receive amplified light from said flared waveguide, said grating having a period different from that of said grating reflectors, thereby producing a coherent single mode output beam.
Claim 32
Dependent Claim
34 words
The device of claim 27 further comprising an array of phase control electrodes located on said substrate between said flared waveguide and said second-order grating, said arrays supplying a set of adjustable injection currents.
Claim 33
Dependent Claim
18 words
The device of claim 27 further comprising an unpumped absorbing region at an end of the second-order grating.
Claim 34
Dependent Claim
12 words
The device of claim 27 wherein said grating reflectors are first-order gratings.
Claim 35
Dependent Claim
12 words
The device of claim 27 wherein said grating reflectors are second-order gratings.
Claim 36
Dependent Claim
24 words
The device of claim 27 wherein a front one of said grating reflectors is a short broadband grating with at most 30% effective reflectivity.
Claim 37
Dependent Claim
18 words
The device of claim 27 wherein said substrate is GaAs and said laser has an InGaAs active region.
Claim 38
Dependent Claim
155 words
A master oscillator power amplifier device comprising, a semiconductor diode laser formed on a substrate, the laser having a waveguide supporting a single spatial mode of propagation, the laser also having a pair of grating reflectors, a rear one of the grating reflectors being characterized by strong frequency selectivity, said laser being wavelength tunable with a variable tuning current injected through said rear reflector, a network of branching single mode waveguides on said substrate connected by Y-junctions, said network optically coupled to the laser and dividing into multiple optical paths, a linear array of amplifiers on said substrate optically coupled to said multiple paths, said amplifiers being an array of electrically pumped single mode waveguides, and a grating output coupler disposed to receive amplified light from said linear array, said coupler having a grating period different from that of said grating reflectors of said laser, thereby producing an array of coherent single mode output beams.
Claim 39
Dependent Claim
155 words
A master oscillator power amplifier device comprising, a semiconductor diode laser formed on a substrate, the laser having a waveguide supporting a single spatial mode of propagation, the laser also having a pair of grating reflectors, a rear one of the grating reflectors being characterized by strong frequency selectivity, said laser being wavelength tunable with a variable tuning current injected through said rear reflector, a network of branching single mode waveguides on said substrate connected by Y-junctions, said network optically coupled to the laser and dividing into multiple optical paths, a linear array of amplifiers on said substrate optically coupled to said multiple paths, said amplifiers being an array of electrically pumped single mode waveguides, and a grating output coupler disposed to receive amplified light from said linear array, said coupler having a grating period different from that of said grating reflectors of said laser, thereby producing an array of coherent single mode output beams.
Claim 40
Dependent Claim
34 words
The device of claim 34 further comprising means disposed between said linear array of amplifiers and said grating output coupler for adjusting the relative phase between laterally adjacent portions of lightwaves from said amplifiers.
Claim 41
Dependent Claim
19 words
The device of claim 34 further comprising an unpumped absorbing region at an end of said grating output coupler.
Claim 42
Dependent Claim
18 words
The device of claim 34 wherein said substrate is GaAs and said laser has an InGaAs active region.
Claim 43
Dependent Claim
24 words
The device of claim 34 wherein a front one of said grating reflectors is a short broadband grating with at most 30% effective reflectivity.
Claim 44
Dependent Claim
17 words
The device of claim 34 wherein said branching network is electrically pumpable via a broad area electrode.
Claim 45
Dependent Claim
187 words
A master oscillator power amplifier device comprising, a semiconductor diode laser disposed on a substrate, said laser having at least one active region for lightwave generation, a waveguide for propagation of said lightwaves, and a pair of grating reflectors, a rear one of said reflectors being characterized by strong frequency selection, said laser being wavelength tunable with a variable tuning current injected through said rear reflector, and a sequential chain of optical amplifiers and grating output couplers disposed in tandem on said substrate, each of said amplifiers including an active region, a waveguide, and means for pumping said active region to amplify said lightwaves, a first of said amplifiers being disposed in tandem with said laser and having said waveguide optically coupled to said laser to receive said lightwaves, the subsequent amplifiers having said waveguide optically coupled to a preceding grating output coupler, each grating output coupler being disposed to receive amplified lightwaves from a preceding amplifier, each grating output coupler having a grating period different from that of said grating reflectors of said laser, each grating output coupler thereby producing a coherent single mode output beam.
Claim 46
Dependent Claim
187 words
A master oscillator power amplifier device comprising, a semiconductor diode laser disposed on a substrate, said laser having at least one active region for lightwave generation, a waveguide for propagation of said lightwaves, and a pair of grating reflectors, a rear one of said reflectors being characterized by strong frequency selection, said laser being wavelength tunable with a variable tuning current injected through said rear reflector, and a sequential chain of optical amplifiers and grating output couplers disposed in tandem on said substrate, each of said amplifiers including an active region, a waveguide, and means for pumping said active region to amplify said lightwaves, a first of said amplifiers being disposed in tandem with said laser and having said waveguide optically coupled to said laser to receive said lightwaves, the subsequent amplifiers having said waveguide optically coupled to a preceding grating output coupler, each grating output coupler being disposed to receive amplified lightwaves from a preceding amplifier, each grating output coupler having a grating period different from that of said grating reflectors of said laser, each grating output coupler thereby producing a coherent single mode output beam.
Claim 47
Dependent Claim
17 words
The device of claim 1 wherein said amplifier means is integral with said detuned grating output amplifier.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-03-25 | 1994-09-24 | 1995-03-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-03-25 | 1998-09-24 | 1999-03-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-03-25 | 2002-09-24 | 2003-03-26 | $7700.00 | Window Closed / Lapsed |