Dr. James N. Walpole Profile

Dr. James N. Walpole

Retired

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Author

Publications (15)

Proceedings Article | 11 May 2004 Paper

Slab-coupled optical waveguide lasers: a review

James Walpole

Proceedings Volume 5365, (2004) https://doi.org/10.1117/12.531078

KEYWORDS: Semiconductor lasers, Semiconducting wafers, Waveguides, Single mode fibers, Beam shaping, Near field, Reflectivity, Diffraction, Laser optics

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Proceedings Article | 4 December 2002 Paper

Slab-coupled semiconductor lasers with a single-spatial large-diameter mode

Joseph Donnelly, Robin Huang, James Walpole, Leo Missaggia, Christopher Harris, Robert Bailey, Jason Plant, Daniel Mull, William Goodhue, Patrick Taylor, Antonio Napoleone, George Turner

Proceedings Volume 4871, (2002) https://doi.org/10.1117/12.460476

KEYWORDS: Semiconductor lasers, Waveguides, Etching, Near field, Quantum efficiency, Aluminum, Quantum wells, Single mode fibers, Measurement devices

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Proceedings Article | 18 April 2000 Paper

High-brightness tapered laser sources in the 1.3- to 2.0-um wavelength range

James Walpole, Joseph Donnelly, H. Choi, Zong-Long Liau, Leo Missaggia, Robert Bailey, Steven Groves, George Turner, Patrick Taylor, Vincento Daneu

Proceedings Volume 3947, (2000) https://doi.org/10.1117/12.382105

KEYWORDS: Laser vision correction, Laser countermeasures, Copper, Microlens, Semiconductor lasers, Semiconducting wafers, Near field, Single mode fibers, Laser sources, Fiber lasers

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Proceedings Article | 7 April 1998 Paper

High-power 1.5-um tapered-gain-region lasers

Joseph Donnelly, James Walpole, Steven Groves, Robert Bailey, Leo Missaggia, Antonio Napoleone, R. Reeder, Christopher Cook

Proceedings Volume 3284, (1998) https://doi.org/10.1117/12.304466

KEYWORDS: Quantum wells, High power lasers, Transparency, Near field, Amplifiers, GRIN lenses, Etching, Reactive ion etching, Quantum efficiency

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Proceedings Article | 7 April 1998 Paper

Low-threshold high-power high-brightness GaInAsSb/AlGaAsSb quantum well lasers emitting at 2.05 um

Hong Choi, George Turner, James Walpole, M. Manfra, M. Connors, Leo Missaggia

Proceedings Volume 3284, (1998) https://doi.org/10.1117/12.304462

KEYWORDS: Continuous wave operation, Semiconductor lasers, Pulsed laser operation, Semiconducting wafers, Cladding, Laser damage threshold, Quantum wells, Quantum efficiency, Reflectivity, High power lasers

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Proceedings Article | 2 May 1997 Paper

High-power 1.3um InGaAsP/InP lasers and amplifiers with tapered gain regions

James Walpole, Gary Betts, Joseph Donnelly, Steven Groves

Proceedings Volume 3001, (1997) https://doi.org/10.1117/12.273818

KEYWORDS: Optical amplifiers, Sensors, High power lasers, Etching, Amplifiers, Continuous wave operation, Quantum wells, Reactive ion etching, Interference (communication), Waveguides

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Proceedings Article | 1 June 1994 Paper

Recent progress with tapered-gain-region devices

Jeffrey Livas, Stephen Chinn, Emily Kintzer, James Walpole, Christine Wang, Leo Missaggia

Proceedings Volume 2148, (1994) https://doi.org/10.1117/12.176603

KEYWORDS: Optical amplifiers, Fiber lasers, Fiber amplifiers, Collimation, Semiconductor lasers, Single mode fibers, Fiber couplers, Fiber coupled lasers, Wavelength division multiplexing, Optical fibers

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Proceedings Article | 16 June 1993 Paper

Single-spatial-mode tapered amplifiers and oscillators

James Walpole, Emily Kintzer, Stephen Chinn, Christine Wang, Leo Missaggia

Proceedings Volume 1850, (1993) https://doi.org/10.1117/12.146929

KEYWORDS: Optical amplifiers, Oscillators, Semiconductor lasers, Diffraction, Laser applications, Technologies and applications, Semiconductors, Amplifiers, Continuous wave operation

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The recent development of semiconductor diode optical amplifiers and lasers having a laterally tapered gain region has changed the outlook for high-power semiconductor optical sources. For the first time, highbrightness, single-element, all-semiconductor sources which emit several watts of cw power in a nearly ideal, single-lobed, diffraction-limited beam have been demonstrated. As semiconductor sources these devices have the inherent advantages of high efficiency, small size, light weight, and reliability. The amplifier12 and all-semiconductor master-oscillator power-amplifier (MOPA) devices34 have gain regions linearly tapered from a few micrometers at the amplifier input to several hundred micrometers at the output. Device lengths are typically 2 mm or more. The angle of the taper is chosen to match the diffraction angle of the input beam which has its waist near the narrow end of the taper. Such a structure is shown schematically in Fig. 1 . The etched grooves have angled side walls and act as cavity spoilers, designed to prevent oscillation of the device as a broad-area laser. The devices are fabricated in single-quantum-well strained-layer InGaAs/AlGaAs graded-index separate-confinement heterostructure laser wafers grown by organometallic vapor phase epitaxy.5 The tapered devices also operate as laser oscillators6 by increasing the input facet reflectivity. For amplifiers, both the input and output facets are coated for low reflectivity (in Fig. 1 , Ri = R2 = 1%), but for oscillators, the input facet is left uncoated (R1 —30%). The oscillators also emit several watts of cw power into a nearly single-lobed, nearly diffraction-limited beam, though their beam quality is usually somewhat inferior to that obtained for amplifiers, particularly at the highest output powers. The lateral mode of the oscillator is similar to the modes described by Fox and Li7 for unstable resonators, except that the semiconductor medium has a significant effect on the self-consistent mode which oscillates. A beam propagation calculation has been carried out to model these effects, as described below. This paper includes a review of the properties of both tapered amplifiers and oscillators.

Proceedings Article | 16 February 1993 Paper

InGaAs/AlGaAs strained quantum-well diode lasers

Christine Wang, Hong Choi, James Walpole, Emily Kintzer, Stephen Chinn, Dean Tsang, John Woodhouse, Joseph Donnelly

Proceedings Volume 1788, (1993) https://doi.org/10.1117/12.141105

KEYWORDS: Semiconductor lasers, Optical amplifiers, Laser damage threshold, Sensors, Quantum efficiency, Gallium arsenide, Indium arsenide, Heterojunctions, Continuous wave operation, High power lasers

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Proceedings Article | 16 February 1993 Paper

Development of GaInAsP/GaAs strained-layer quantum-well diode lasers

Steven Groves, Zong-Long Liau, Susan Palmateer, James Walpole, Leo Missaggia

Proceedings Volume 1788, (1993) https://doi.org/10.1117/12.141096

KEYWORDS: Gallium arsenide, Quantum wells, Indium gallium phosphide, Waveguides, Semiconductor lasers, Indium gallium arsenide, Sensors, Cladding, Semiconducting wafers, Laser damage threshold

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Proceedings Article | 1 July 1991 Paper

Low-threshold grating surface-emitting laser arrays

Gary Evans, Nils Carlson, David Bour, So Liew, Robert Amantea, Christine Wang, Hong Choi, James Walpole, Jerome Butler, W. Ferguson

Proceedings Volume 1418, (1991) https://doi.org/10.1117/12.43827

KEYWORDS: Quantum efficiency, Semiconductor lasers, Continuous wave operation, Quantum wells, Laser applications, Coating, Heterojunctions, Gallium arsenide, Pulsed laser operation

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Proceedings Article | 1 January 1991 Paper

Fabrication and characterization of semiconductor microlens arrays

Vicky Diadiuk, Zong-Long Liau, James Walpole

Proceedings Volume 1354, (1991) https://doi.org/10.1117/12.47888

KEYWORDS: Semiconductor lasers, Microlens, Semiconductors, Microlens array, Binary data, Wet etching, Etching, Phosphorus, Chemical species, Photography

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Proceedings Article | 1 May 1990 Paper

High-power hybrid two-dimensional surface-emitting AlGaAs diode laser arrays

Joseph Donnelly, Kurt Rauschenbach, Christine Wang, Robert Bailey, James Walpole, Leo Missaggia, John Woodhouse, Hong Choi, F. O'Donnell, Vicky Diadiuk

Proceedings Volume 1219, (1990) https://doi.org/10.1117/12.18263

KEYWORDS: Laser applications, Semiconductor lasers, Silicon, Pulsed laser operation, Continuous wave operation, Laser damage threshold, High power lasers, Semiconducting wafers, Gallium arsenide

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Proceedings Article | 1 May 1990 Paper

Fabrication of microlenses in compound semiconductors and monolithic integration with diode lasers

Zong-Long Liau, James Walpole, Vicky Diadiuk, Daniel Mull, Leo Missaggia

Proceedings Volume 1219, (1990) https://doi.org/10.1117/12.18265

KEYWORDS: Microlens, Mirrors, Semiconductor lasers, Semiconducting wafers, Laser applications, Waveguides, Lens design, Spherical lenses, Compound semiconductors, Wet etching

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Proceedings Article | 1 May 1990 Paper

External-cavity coherent operation of InGaAsP buried-hetereostructure laser array

Vicky Diadiuk, Zong-Long Liau, James Walpole, J. Caunt, Richard Williamson

Proceedings Volume 1219, (1990) https://doi.org/10.1117/12.18274

KEYWORDS: Spatial filters, Microlens array, Mirrors, Laser applications, Laser damage threshold, Semiconductor lasers, Antireflective coatings, Microlens, Photography, Ferroelectric materials

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Showing 5 of 15 publications

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