Prof. P. Daniel Dapkus Profile

Prof. P. Daniel Dapkus

Professor at Univ of Southern California

SPIE Involvement:

Author

Proceedings Article | 10 September 2014 Paper

Formation of Fabry-Perot cavity in one-dimensional and two-dimensional GaAs nanostructures

Chongwu Zhou, Shermin Arab, Maoqing Yao, ChunYung Chi, P. Daniel Dapkus, Stephen Cronin

Proceedings Volume 9168, 91680C (2014) https://doi.org/10.1117/12.2074531

KEYWORDS: Gallium arsenide, Nanostructures, Silicon, Fabry–Perot interferometers, Optical resonators, Gold, Liquids, Metalorganic chemical vapor deposition, Semiconductor lasers, Nanowires

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Proceedings Article | 19 February 2014 Paper

Optical and electrical characterization of surface passivated GaAs nanostructures

Maoqing Yao, Chia-Chi Chang, Shermin Arab, Chun Yung Chi, P. Daniel Dapkus, Stephen Cronin

Proceedings Volume 8996, 89960G (2014) https://doi.org/10.1117/12.2040999

KEYWORDS: Gallium arsenide, Nanostructures, Liquids, Silicon, Solar cells, Metalorganic chemical vapor deposition, Diffusion, Semiconductor lasers, Hybrid silicon lasers, Nanowires

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Proceedings Article | 3 May 2012 Paper

Scalable synthesis of vertically aligned, catalyst-free gallium arsenide nanowire arrays: towards optimized optical absorption

Maoqing Yao, ChunYung Chi, Chenxi Lin, P. Daniel Dapkus, Anuj Madaria, Chongwu Zhou, Michelle Povinelli, Ningfeng Huang

Proceedings Volume 8373, 837314 (2012) https://doi.org/10.1117/12.919283

KEYWORDS: Gallium arsenide, Reflection, Scanning electron microscopy, Absorption, Photomasks, Semiconductors, Reflectivity, Metals, Electron beam lithography, Nanowires

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Proceedings Article | 3 June 2005 Paper

Photonic crystal devices

M.-H. Shih, J. O'Brien, W. Kuang, J. Cao, M. Bagheri, P. Dapkus, S. Choi

Proceedings Volume 5825, (2005) https://doi.org/10.1117/12.611348

KEYWORDS: Waveguides, Photonic crystals, Laser crystals, Sapphire, Continuous wave operation, Reflectivity, Semiconductor lasers, Laser resonators, Optical microcavities, Modulation

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Proceedings Article | 1 April 2005 Paper

Bus-coupled microresonator lasers

Qi Yang, Zhen Peng, Sang Jun Choi, Seung-June Choi, P. Dapkus

Proceedings Volume 5738, (2005) https://doi.org/10.1117/12.590836

KEYWORDS: Waveguides, Resonators, Microresonators, Photonic integrated circuits, Continuous wave operation, Laser resonators, Semiconductors, Tunable lasers, Quantum wells, Wavelength division multiplexing

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Proceedings Article | 15 April 2003 Paper

Photonic crystal lasers

Woo-Jun Kim, Paul Dapkus, John O'Brien, Sang-Jun Choi, Po-Tsung Lee, Cheolwoo Kim, Tian Yang, W. Kuang, Jiang-Rong Cao

Proceedings Volume 4942, (2003) https://doi.org/10.1117/12.470908

KEYWORDS: Photonic crystals, Laser crystals, Photomasks, Etching, Semiconductors, Optical pumping, Polymethylmethacrylate, Optical microcavities, Finite-difference time-domain method, Laser resonators

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Photonic crystal microcavity lasers are potentially attractive optical sources for future communication systems. They operate at lithographically defined wavelengths and because of their small volumes they are expected to exhibit low operating powers. Much work remains to be done, however, in order for these sources to find mainstream applications. In this presentation we will report on our work on optically pumped photonic crystal lasers. Finite-difference time-domain and finite element simulations will be presented as part of a discussion of the resonant cavity design. The trade-offs in the design of photonic lattice hole radius and membrane thickness will also be included, and we will discuss strategies for minimizing the optical loss in these cavities. The photonic crystal laser cavities reported here are defined by electron beam lithography in pmma. The pmma is subsequently used as a mask to transfer the pattern into a Cr/Au layer in an ion beam milling step. This patterned metal layer is then used as a mask for a reactive ion etch that patterns a silicon nitride layer. Finally this layer is used as a mask to transfer the lattice into the InGaAsP semiconductor using an ECR etching step. Suspended membranes are formed by chemically undercutting the lattice. This provides strong optical confinement at the semiconductor/air interfaces at the top and bottom of the cavity. We have demonstrated pulsed, optically pumped lasing at and above room temperature in these resonant cavities using a semiconductor diode laser as the pump. The resonant cavity in our demonstration is formed by removing 19 holes from a triangular lattice and is about 2.6 mm across. Incident threshold pump powers for this cavity size as low as 0.5 mW have been demonstrated at room temperature. The peak output power collected through an optical fiber is approximately 2 mW. Lasing is seen for pump pulses as long as 200 ns. We have also demonstrated lasing in these cavities at elevated substrate temperatures. This demonstration was done using an 860 nm top emitting VCSEL as the pumping source because we expect it to provide a direction towards monolithic, electrically addressable lasers. Input power versus output power lasing characteristics for substrate temperatures up to 50 °C have been obtained. We will also report on our work on lithographic fine-tuning of the lasing wavelength. This wavelength can be defined through the lattice constant or the hole radius. This feature of photonic crystal lasers allows the definition of multiwavelength arrays. We have built and characterized arrays in which the lattice constant varies 2 nm steps across the array. The lasing wavelength redshifts with increasing lattice constant with an average separation between adjacent lasing wavelengths of 4.6 nm. The lasing wavelength tunes through the gain spectrum before the laser mode hops. Finally, we will present data on the optical loss in these cavities obtained by varying the number of lattice periods. We observed a reduction in incident threshold pump powers with increasing number of lattice periods at least through 11 periods.

Proceedings Article | 13 April 1999 Paper

All-optical routing schemes for networks using wavelength-recognizing switches

Alexander Sawchuk, Serge Dubovitsky, Bogdan Hoanca, Daniel Zhu, Paul Dapkus, William Steier

Proceedings Volume 3632, (1999) https://doi.org/10.1117/12.344606

KEYWORDS: Switches, Switching, Waveguides, Control systems, Wavelength division multiplexing, Wave propagation, Optical amplifiers, Signal to noise ratio, Tunable lasers, Data modeling

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We have recently described a wavelength-recognizing switch (WRS) which we showed to be capable of truly all-optical routing. Although other authors had previously reported "all-optical" networks [1, 2, 3], the term has generally referred to all—optical data paths only. In such implementations only the data remains in optical format as it propagates along the network paths. Optical-to-electronic conversions are still allowed for what is termed "control signals," namely address bits and additional signaling entities, which are assumed to have lower speed than the data. In contrast, the WRS we presented has the capability to route data by interpreting the control signals in the optical domain, thus avoiding the overhead and the latency ofthe optic-to-electronic conversion. In a series of previous publications [4, 5] we demonstrated the experimental viability of the WRS and measured some of the relevant system parameters of the device. More recently, we published details on how the device could be used to build multistage all-optical self-routing networks. We also developed a simulation model and estimated the maximum number of stages that can be cascaded in such networks. The work presented in this paper carries the simulation results one step further, and investigates some of the possible topologies that can be used for WRS networks, as well as the system implications of these topologies. To facilitate a better understanding of the concepts presented, we briefly review the device functionality and the main experimental results that affect the system performance. We then show how to implement some of the building blocks we use in the self-routing topologies, and explain the equalization mechanism necessary for using WRS in multistage networks. We then compare the practical advantages of the topologies of interest and decide which topology is the most probable implementation. Finally we present details on a new generation of WRS, which is waveguide based, thus more easily fabricated and integrated with optical fiber systems

Proceedings Article | 4 December 1998 Paper

Fabrication of traveling-wave semiconductor optical amplifiers for optical switching applications

Serge Dubovitsky, William Steier, Paul Dapkus, Denis Tishinin, Daniel Zhu, Kushant Uppal

Proceedings Volume 3491, (1998) https://doi.org/10.1117/12.328739

KEYWORDS: Optical switching, Semiconductor optical amplifiers, Optical amplifiers, Reflectivity, Antireflective coatings, Switching, Semiconductor lasers, Quantum wells, Laser damage threshold, Chlorine

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Proceedings Article | 4 December 1998 Paper

Differential gain, refractive index and linewidth enhancement factor in broad-area semiconductor optical amplifiers

Denis Tishinin, Paul Dapkus, Kushant Uppal, Serge Dubovitsky, William Steier, Daniel Zhu

Proceedings Volume 3491, (1998) https://doi.org/10.1117/12.328720

KEYWORDS: Refractive index, Semiconductor optical amplifiers, Optical amplifiers, Semiconductor lasers, Waveguides, Fabry–Perot interferometers, Electrical engineering, High power lasers, Spatial coherence, Switches

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Proceedings Article | 1 February 1998 Paper

Multiple long-wavelength VCSEL arrays for low-cost WDM

William Choi, Jack Jewell, A. Jones, Aaron Bond, Lawrence West, David Lin, James Coleman, Stan Swirhun, Paul Dapkus, Charles Roberts

Proceedings Volume 3234, (1998) https://doi.org/10.1117/12.300922

KEYWORDS: Vertical cavity surface emitting lasers, Wavelength division multiplexing, Transmitters, Semiconducting wafers, Multiplexing, Manufacturing, Fiber lasers, Fiber amplifiers, Electronic components, Receivers

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Proceedings Article | 1 June 1994 Paper

Low-threshold InGaAs/GaAs single-quantum-well lasers using single-step metalorganic chemical vapor deposition

Paul Dapkus, Sabeur Siala, Richard Nottenburg, Newton Frateschi, Michael MacDougal, Hanmin Zhao, Kushant Uppal

Proceedings Volume 2148, (1994) https://doi.org/10.1117/12.176612

KEYWORDS: Laser damage threshold, Quantum wells, Metalorganic chemical vapor deposition, Continuous wave operation, Photoresist materials, Pulsed laser operation, Gallium arsenide, Doping, External quantum efficiency, Cladding

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Proceedings Article | 16 June 1993 Paper

High-efficiency three-terminal laser array for optical interconnect

Newton Frateschi, Hanmin Zhao, James Elliot, Sabeur Siala, Paul Dapkus, Richard Nottenburg, M. Govindarajan

Proceedings Volume 1850, (1993) https://doi.org/10.1117/12.146915

KEYWORDS: Semiconductor lasers, Switching, Photons, Laser applications, Modulators, Modulation, Bistability, Zinc, Diffusion, Resistance

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Proceedings Article | 16 June 1993 Paper

Effect of strain on 1.5-um quantum-well lasers

Paul Dapkus, Jules Osinski, William Rideout, Yau Zou, Piotr Grodzinski, F. David Crawford, Wayne Sharfin

Proceedings Volume 1850, (1993) https://doi.org/10.1117/12.146902

KEYWORDS: Semiconductor lasers, Temperature metrology, Laser damage threshold, Quantum wells, Transparency, Technologies and applications, Laser applications, Absorption, Measurement devices, Waveguides

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Proceedings Article | 16 February 1993 Paper

Temperature-engineered growth of low-threshold lasers on nonplanar substrates

Paul Dapkus, Newton Frateschi

Proceedings Volume 1788, (1993) https://doi.org/10.1117/12.141114

KEYWORDS: Quantum wells, Gallium arsenide, Laser damage threshold, Fiber lasers, Reflectors, Sensors, External quantum efficiency, Semiconductor lasers, Near field, Heterojunctions

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Proceedings Article | 1 March 1991 Paper

GaAs opto-thyristor for pulsed power applications

Martin Gundersen, Harold Fetterman, Peyman Hadizad, Paul Dapkus, Hanmin Zhao, Steven Hummel, Jung Hur

Proceedings Volume 1378, (1991) https://doi.org/10.1117/12.25066

KEYWORDS: Gallium arsenide, Pulsed power, Switching, Switches, Semiconductor lasers, Silicon, Inductance, Liquid phase epitaxy, Photons, Metalorganic chemical vapor deposition

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Showing 5 of 15 publications

Conference Committee Involvement (7)

Optoelectronic Integrated Circuits XV

6 February 2013 | San Francisco, California, United States

Optoelectronic Integrated Circuits XIV

25 January 2012 | San Francisco, California, United States

Optoelectronic Integrated Circuits XIII

26 January 2011 | San Francisco, California, United States

Optoelectronic Integrated Circuits XII

27 January 2010 | San Francisco, California, United States

Optoelectronic Integrated Circuits XI

28 January 2009 | San Jose, California, United States

Showing 5 of 7 Conference Committees

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