We report on the demonstration of holographic data storage (HDS) at a raw areal bit density of 2.2 Tbit/in2. The demonstration was performed on a platform incorporating several new technical innovations. One key innovation – the coherent data channel – was successfully introduced ahead of schedule following encouraging early results. Issues of media recording efficiency and carrier wavefront demodulation for homodyne detection are discussed.
The onslaught of big data continues even as growth in data storage density tapers off. Meanwhile, the physics of holography continues to suggest the possibility of digital data storage at densities far exceeding those of today’s technologies. We report on recent results achieved with a demonstrator platform incorporating several new secondgeneration techniques for increasing holographic data storage (HDS) recording density and speed.
Since the highest reported areal densities for hard disk drive products currently hover in the 1 Tbit/in2 range, we have adopted 2 Tbit/in2 as a milestone likely to generate interest in the technology. The demonstrator is based on an advanced pre-production prototype, and so inherits highly functional electronic, mechanical, and optical subsystems. It employs a high-NA monocular architecture with proven angle-polytopic multiplexing.
The demonstrator design includes several second-generation innovations. The first, dynamic aperture multiplexing, greatly increases the number of multiplexed holograms. The second, the DREDTM medium formulation, provides dramatically higher dynamic range to record these holograms. These two features alone theoretically allow the demonstrator to exceed 2 Tbit/in2. Additionally, it is equipped with the capability of quadrature homodyne detection, permitting phase quadrature multiplexing (QPSK modulation), and the potential to further increase user capacity by a factor of four or more. The demonstrator has thus been designed to achieve densities supporting the multi-terabyte storage capacities required for competitive products, and to demonstrate the potential for Moore’s-Law growth for years to come.
We introduce a new method to make gradient index (GRIN) lenses in diffusive photopolymers with nearly arbitrary two-dimensional (2D) profiles. By modulating the 2D intensity pattern and power of the exposure with a deformable mirror device (DMD), the index profile of the GRIN lens can be controlled. Combined with the self-developing nature of the photophotopolymer, rapid on-demand printing of arbitrary micro-optics is enabled. We demonstrate the process by fabricating quadratic GRIN lenses, Zernike polynomials and multi-focal lenses.
Holographic data storage (HDS) remains an attractive technology for big data. We report on recent results achieved with
a demonstrator platform incorporating several new second-generation techniques for increasing HDS recording density
and speed. This demonstrator has been designed to achieve densities that support the multi-terabyte storage capacities
required for a competitive product. It leverages technology from an existing state-of-the-art pre-production prototype,
while incorporating a new optical head designed to demonstrate several new technical advances.
The demonstrator employs the new technique of dynamic aperture multiplexing in a monocular architecture. In a
previous report, a monocular system employing angle-polytopic multiplexing achieved a recording density over 700
Gbit/in2, exceeding that of contemporaneously shipping hard drives . Dynamic aperture multiplexing represents an
evolutionary improvement with the potential to increase this figure by over 200%, while still using proven anglepolytopic
multiplexing in a monocular architecture.
Additionally, the demonstrator is capable of two revolutionary advances in HDS technology. The first, quadrature
homodyne detection, enables the use of phase shift keying (PSK) for signal encoding, which dramatically improves
recording intensity homogeneity and increases SNR. The second, phase quadrature holographic multiplexing, further
doubles density by recording pairs of holograms in quadrature (QPSK encoding).
We report on the design and construction of the demonstrator, and on the results of current recording experiments.
To compete in the archive and backup industries, holographic data storage must be highly competitive in four critical
areas: total cost of ownership (TCO), cost/TB, capacity/footprint, and transfer rate. New holographic technology
advancements by Akonia Holographics have enabled the potential for ultra-high capacity holographic storage devices
that are capable of world record bit densities of over 2-4Tbit/in2, up to 200MB/s transfer rates, and media costs less than
$10/TB in the next few years. Additional advantages include more than a 3x lower TCO than LTO, a 3.5x decrease in
volumetric footprint, 30ms random access times, and 50 year archive life. At these bit densities, 4.5 Petabytes of
uncompressed user data could be stored in a 19” rack system. A demonstration platform based on these new advances
has been designed and built by Akonia to progressively demonstrate bit densities of 2Tb/in2, 4Tb/in2, and 8Tb/in2 over
the next year.
The realization of a commercial holographic data storage device has remained elusive for many decades. The most recent efforts were by InPhase Technologies between 2001 and 2009 resulting in 52 functioning prototypes capable of 300GB/disk and 20MB/s transfer rates. Despite being the world’s first fully functional holographic drives, the primary competitor to holographic archive storage at that time, LTO, had already achieved 800GB and 120MB/in 2008; and by 2010, LTO had achieved 1.5TB and 140MB/s. This left InPhase at a competitive disadvantage to LTO archive solutions despite other strengths such as robustness, random access, and longer-term archive lifetime.
Looking into the future, holographic data storage must be highly competitive with tape in three critical areas: cost/TB, capacity/footprint, and transfer rate. If this can be achieved, holographic data storage would become a superior solution given the low latencies and overall robustness to propel it into being the archive storage front-runner. New technology advancements by Akonia Holographics have enabled the potential for ultra-high capacity holographic storage devices that are capable of world record bit densities of over 2Tbit/in2, 200-300MB/s transfer rates, and a media cost less than $10/TB in the next 5 years. A demonstration platform based on these new advances has been designed and is currently being built by Akonia to progressively demonstrate bit densities of 2Tb/in2, 4Tb/in2, and 8Tb/in2 over the next year.
A new optical architecture for holographic data storage system which is compatible with a Blu-ray Disc™ (BD) system is proposed. In the architecture, both signal and reference beams pass through a single objective lens with numerical aperture (NA) 0.85 for realizing angularly multiplexed recording. The geometry of the architecture brings a high affinity with an optical architecture in the BD system because the objective lens can be placed parallel to a holographic medium. Through the comparison of experimental results with theory, the validity of the optical architecture was verified and demonstrated that the conventional objective lens motion technique in the BD system is available for angularly multiplexed recording. The test-bed composed of a blue laser system and an objective lens of the NA 0.85 was designed. The feasibility of its compatibility with BD is examined through the designed test-bed.
Tunnels are a challenging environment for radio communications. In this paper we consider the use of autonomous
mobile radio nodes (AMRs) to provide wireless tethering between a base station and a leader in a tunnel exploration
scenario. Using a realistic, experimentally-derived underground radio signal propagation model and a tethering
algorithm for AMR motion control based on a consensus variable protocol, we present experimental results involving a
tele-operated leader with one or two followers. Using radio signal strength measurements, the followers autonomously
space themselves so as to achieve equal radio distance between each entity in the chain from the base to the leader.
Results show the feasibility of our ideas.
The promise of using volume holography to deliver high performance optical storage systems is at hand. The possibility of extremely large storage capacities and fast transfer rates make holographic storage ideal for high performance video applications. An overview of advances at InPhase Technologies is presented. Progress toward high-density implementations as well as the development of a functional prototype is presented. These systems are the first fully functional holographic recordable drives developed. Their development paves the way for the commercialization of this technology.
An overview of the InPhase Technologies holographic demonstration platform is reviewed and a new holographic multiplexing technique presented. The platform is a compact, mobile system and the first fully functional, portable; holographic recordable drive complete with custom optics and control and channel electronics. In addition a description of "POLYTOPIC MULTIPLEXING" is presented. This innovation allows us to simplify the system geometry and optimize the media usage enabling a sustainable product road map. These developments pave the way for the commercialization of this technology.
An overview of the InPhase Technologies holographic demonstration platform is presented. This compact, mobile system is a fully functional holographic recordable drive complete with custom optics and custom control and channel electronics. The development of this device paves the way for the commercialization of this technology.
In this paper we show how to use holographic photon echoes for the implementation of a variety of optical processing functions, including scanners, spectrum analyzers, time- integrating correlators, folded spectrum analyzers, ambiguity function processors, image sequence correlators, and folded image raster correlators. The combination of optical coherent transients operating as spatial-spectral holograms with acoustooptic deflectors and electrooptic modulators allows a variety of optical architectures to be implemented with substantially enhanced performance and functionality beyond that achievable by these technologies individually. We show how to utilize the basic architectures presented here as building blocks of more powerful and complex real-time optical processing systems.