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Papers by Dipayan Choudhary

Research paper thumbnail of III-nitride nanowire light-emitting diodes: design and characterization

III-NITRIDE NANOWIRE LIGHT-EMITTING DIODES: DESIGN AND CHARACTERIZATION by Dipayan Datta Choudhar... more III-NITRIDE NANOWIRE LIGHT-EMITTING DIODES: DESIGN AND CHARACTERIZATION by Dipayan Datta Choudhary III-nitride semiconductors have been intensively studied for optoelectronic devices, due to the superb advantages offered by this materials system. The direct energy bandgap III-nitride semiconductors can absorb or emit light efficiently over a broad spectrum, ranging from 0.65 eV (InN) to 6.4 eV (AlN), which encompasses from deep ultraviolet to near infrared spectrum. However, due to the lack of native substrates, conventional III-nitride planar heterostructures generally exhibit very high dislocation densities that severely limit the device performance and reliability. On the other hand, nanowire heterostructures can be grown on lattice mismatched substrates with drastically reduced dislocation densities, due to highly effective lateral stress relaxation. Nanowire light-emitting diodes (LEDs) with emission in the ultraviolet to visible wavelength range have recently been studied for ...

Research paper thumbnail of Laser communication data storage using angle multiplexing and spatial division multiplexing

Free-Space Laser Communications XXXIII, 2021

The need for data storage is rising exponentially – 90% of the world’s data has been created in t... more The need for data storage is rising exponentially – 90% of the world’s data has been created in the last two years and almost 5% of the world’s electricity consumption is currently devoted to storing this massive amount of data. LyteLoop is developing a disruptive alternative to data storage technology using optical communications to store data in motion between objects with higher security and lower power consumption. The technology relies on a patented method of dramatically extending optical path length called Angle Multiplexing, as well as spatial division multiplexing with orbital angular momentum modes to increase data rate in order to store data in space, in optical fiber, or in free-space vacuum cavities. A free-space prototype is under development, which stores data using a high bit rate signal continuously circulating through an Angle Multiplexing system.

Research paper thumbnail of High capacity and access rate, data storage using laser communications

Optical Engineering, 2021

The amount of data in the world is expanding exponentially. About 90% of the world's data has bee... more The amount of data in the world is expanding exponentially. About 90% of the world's data has been created in the last two years, and almost 5% percent of the world's power is used for data storage and computing. Lyteloop has an approach to data storage that uses optical communications to store data in motion between objects. Since the speed of light is fast, one needs very high data rates and very long paths to store large amounts of data. Data storage of petabytes, and even exabytes, is reasonable with this approach, in a format more compact than traditional data storage methods. LyteLoop has demonstrated an operating system using fiber, and currently has a system operating using free space. The fiber system stores >1 Gbyte, using 2000 km of fiber, and allows us to develop data center-like writing and retrieval experiences. Multiple patents have been filed with some granted. One of the patented concepts is called angle multiplexing, a method of dramatically increasing path length over a free-space path among multiple optical apertures. This has been demonstrated in free space using two different approaches. LyteLoop can store data in fiber, and in free space, either in a vacuum or in space.

Research paper thumbnail of Lyteloop data “storage in motion”

This paper presents a patent pending approach to store digital data using high bandwidth laser li... more This paper presents a patent pending approach to store digital data using high bandwidth laser light in motion. Data is stored in a loop. The amount of data stored is the data rate times the storage time. Lyteloop uses: (i) highly multiplexed optical communications to maximize data rate, and (ii) a long light path, to maximize length of time it takes light to traverse the full storage loop. Lyteloop is developing data storage in motion in 4 domains : fiber, space, and two forms of near vacuum chambers. Multiplexing is done across very wide wavelength ranges, and many spatial modes. OEM modes will be used in free space at the shorter wavelengths, and other spatial mode structures will be used in fibers. Multiple cores will be used in fibers. A 1.5 Gigabyte demonstation data storage unit has been built in fiber, and is described, along with its performance. We are starting a free space prototype. Lyteloop builds on, and advances, both free space, and fiber, high data rate communicatio...

Research paper thumbnail of A revolutionary optical hyper data center using ultra-high data rate laser communications

LyteLoop is developing data storage in motion using Petabyte per second data rate optical communi... more LyteLoop is developing data storage in motion using Petabyte per second data rate optical communications in 4 domains: space, fiber, and two free space vacuum cavities. The amount of data in the world is expanding exponentially. 90% of the world’s data has been created in the last 2 years. 4-5% of the world’s power is currently being used by data storage and computing. We need more efficient methods of data storage. Physical sites can be subject to attack, and to local laws. Data storage that avoids these constraints is desirable. This is a revolutionary approach to data storage, using optical communications as a base. Data is not stored in an object. It is stored in motion between objects. The speed of light is fast, so to store data in motion we need very high data rates, and very long paths. LyteLoop has had an operating system using fiber and is currently building a free-space storage prototype. The current fiber system stores > 1 GByte, using 2000 Km of fiber, and is allowin...

Research paper thumbnail of Lyteloop data "storage in motion" using high-bandwidth laser communications

This paper presents a patent pending approach to store digital data using high bandwidth laser li... more This paper presents a patent pending approach to store digital data using high bandwidth laser light in motion. Data will be stored in a loop. The higher the data rate, and the longer the storage loop, the more data can be stored. We plan to use : (i) highly multiplexed optical communications to maximize data rate, and (ii) a long light path, to maximize length of time it takes light to traverse the full storage loop. Lyteloop is developing data storage in motion in 4 domains : fiber, space, and two forms of near vacuum cavities. Three of those domains are in a free space near vacuum. Multiplexing will be done across very wide wavelength ranges, and many spatial modes will be used. OEM modes will be used in free space at the shorter wavelengths, and spatial division multiplexing (SDM) in fibers. Multiple cores will be used in fibers A 1.5 Gigabyte demonstation data storage unit has been built in fiber. This démonstration unit, and its performance, is described. Lyteloop will build o...

Research paper thumbnail of III-nitride nanowire light-emitting diodes: design and characterization

III-NITRIDE NANOWIRE LIGHT-EMITTING DIODES: DESIGN AND CHARACTERIZATION by Dipayan Datta Choudhar... more III-NITRIDE NANOWIRE LIGHT-EMITTING DIODES: DESIGN AND CHARACTERIZATION by Dipayan Datta Choudhary III-nitride semiconductors have been intensively studied for optoelectronic devices, due to the superb advantages offered by this materials system. The direct energy bandgap III-nitride semiconductors can absorb or emit light efficiently over a broad spectrum, ranging from 0.65 eV (InN) to 6.4 eV (AlN), which encompasses from deep ultraviolet to near infrared spectrum. However, due to the lack of native substrates, conventional III-nitride planar heterostructures generally exhibit very high dislocation densities that severely limit the device performance and reliability. On the other hand, nanowire heterostructures can be grown on lattice mismatched substrates with drastically reduced dislocation densities, due to highly effective lateral stress relaxation. Nanowire light-emitting diodes (LEDs) with emission in the ultraviolet to visible wavelength range have recently been studied for ...

Research paper thumbnail of Laser communication data storage using angle multiplexing and spatial division multiplexing

Free-Space Laser Communications XXXIII, 2021

The need for data storage is rising exponentially – 90% of the world’s data has been created in t... more The need for data storage is rising exponentially – 90% of the world’s data has been created in the last two years and almost 5% of the world’s electricity consumption is currently devoted to storing this massive amount of data. LyteLoop is developing a disruptive alternative to data storage technology using optical communications to store data in motion between objects with higher security and lower power consumption. The technology relies on a patented method of dramatically extending optical path length called Angle Multiplexing, as well as spatial division multiplexing with orbital angular momentum modes to increase data rate in order to store data in space, in optical fiber, or in free-space vacuum cavities. A free-space prototype is under development, which stores data using a high bit rate signal continuously circulating through an Angle Multiplexing system.

Research paper thumbnail of High capacity and access rate, data storage using laser communications

Optical Engineering, 2021

The amount of data in the world is expanding exponentially. About 90% of the world's data has bee... more The amount of data in the world is expanding exponentially. About 90% of the world's data has been created in the last two years, and almost 5% percent of the world's power is used for data storage and computing. Lyteloop has an approach to data storage that uses optical communications to store data in motion between objects. Since the speed of light is fast, one needs very high data rates and very long paths to store large amounts of data. Data storage of petabytes, and even exabytes, is reasonable with this approach, in a format more compact than traditional data storage methods. LyteLoop has demonstrated an operating system using fiber, and currently has a system operating using free space. The fiber system stores >1 Gbyte, using 2000 km of fiber, and allows us to develop data center-like writing and retrieval experiences. Multiple patents have been filed with some granted. One of the patented concepts is called angle multiplexing, a method of dramatically increasing path length over a free-space path among multiple optical apertures. This has been demonstrated in free space using two different approaches. LyteLoop can store data in fiber, and in free space, either in a vacuum or in space.

Research paper thumbnail of Lyteloop data “storage in motion”

This paper presents a patent pending approach to store digital data using high bandwidth laser li... more This paper presents a patent pending approach to store digital data using high bandwidth laser light in motion. Data is stored in a loop. The amount of data stored is the data rate times the storage time. Lyteloop uses: (i) highly multiplexed optical communications to maximize data rate, and (ii) a long light path, to maximize length of time it takes light to traverse the full storage loop. Lyteloop is developing data storage in motion in 4 domains : fiber, space, and two forms of near vacuum chambers. Multiplexing is done across very wide wavelength ranges, and many spatial modes. OEM modes will be used in free space at the shorter wavelengths, and other spatial mode structures will be used in fibers. Multiple cores will be used in fibers. A 1.5 Gigabyte demonstation data storage unit has been built in fiber, and is described, along with its performance. We are starting a free space prototype. Lyteloop builds on, and advances, both free space, and fiber, high data rate communicatio...

Research paper thumbnail of A revolutionary optical hyper data center using ultra-high data rate laser communications

LyteLoop is developing data storage in motion using Petabyte per second data rate optical communi... more LyteLoop is developing data storage in motion using Petabyte per second data rate optical communications in 4 domains: space, fiber, and two free space vacuum cavities. The amount of data in the world is expanding exponentially. 90% of the world’s data has been created in the last 2 years. 4-5% of the world’s power is currently being used by data storage and computing. We need more efficient methods of data storage. Physical sites can be subject to attack, and to local laws. Data storage that avoids these constraints is desirable. This is a revolutionary approach to data storage, using optical communications as a base. Data is not stored in an object. It is stored in motion between objects. The speed of light is fast, so to store data in motion we need very high data rates, and very long paths. LyteLoop has had an operating system using fiber and is currently building a free-space storage prototype. The current fiber system stores > 1 GByte, using 2000 Km of fiber, and is allowin...

Research paper thumbnail of Lyteloop data "storage in motion" using high-bandwidth laser communications

This paper presents a patent pending approach to store digital data using high bandwidth laser li... more This paper presents a patent pending approach to store digital data using high bandwidth laser light in motion. Data will be stored in a loop. The higher the data rate, and the longer the storage loop, the more data can be stored. We plan to use : (i) highly multiplexed optical communications to maximize data rate, and (ii) a long light path, to maximize length of time it takes light to traverse the full storage loop. Lyteloop is developing data storage in motion in 4 domains : fiber, space, and two forms of near vacuum cavities. Three of those domains are in a free space near vacuum. Multiplexing will be done across very wide wavelength ranges, and many spatial modes will be used. OEM modes will be used in free space at the shorter wavelengths, and spatial division multiplexing (SDM) in fibers. Multiple cores will be used in fibers A 1.5 Gigabyte demonstation data storage unit has been built in fiber. This démonstration unit, and its performance, is described. Lyteloop will build o...