Sergei Orlov

Stanford University | SU

We performed a parametric study to suppress secondary phases in lithium niobate thin films by using pulsed laser deposition (PLD). A KrF excimer laser (λ,=248nm) was used as a PLD source and c-oriented sapphire was used as substrates, for waveguide applications. By reducing the growth rate and changing the ambient gas pressure respectively, we foun...

Modern technologies offer new opportunities for experimentalists in a variety of research areas of fluid dynamics. Improvements are now possible in the state-of-the-art in precision, dynamic range, reproducibility, motion-control accuracy, data-acquisition rate and information capacity. These improvements are required for understanding complex turb...

Modern technologies offer new opportunities for experimentalists in a wide variety of research areas including hydrodynamics. A significant improvement in precision, dynamic range, reproducibility, motion control accuracy, data acquisition rate and information capacity of the experimental datasets over the current state-of-the-art are possible usin...

We present new class of modulation codes based on permutation coding which satisfy channel coding constraint suitable for holographic and optical data storage, and simultaneously have strong error correction capability and high code rate efficiency.

Optical data storage is a phenomenal success story. Since its introduction in the early 1980s, optical data storage devices have evolved from being focused primarily on music distribution, to becoming the prevailing data distribution and recording medium. Each year, billions of optical recordable and prerecorded disks are sold worldwide. Almost eve...

We present a new class of modulation codes based on permutation coding which satisfy the channel coding constraint suitable for the digital holographic data storage, and which simultaneously provide strong error correction at high code rates. The channel decoding scheme is based on the true maximum likelihood detection realized using a newly develo...

A single meniscus aspherical lens and air-spaced spherical lenses having negative and positive powers are identified as minimum aberration configurations for page-based holographic recording systems. Further correction of pupil aberrations makes the lens system usable both for holographic and for surface recording, and the lens is realizable by usi...

We present a new experimental platform for studies of turbulence and turbulent mixing in accelerating and rotating fluids. The technology is based on the ultra-high performance optical holographic digital data storage. The state-of-the-art electro-mechanical, electronic, and laser components allow for realization of turbulent flows with high Reynol...

We performed a parametric study to suppress secondary phases in lithium niobate thin films by using pulsed laser deposition (PLD). By reducing the growth rate and changing the ambient gas pressure respectively, we found that the main parameter suppressing secondary phases is controlling the plume strength. For investigating the relation between fil...

We present results of nanosecond laser ablation of silicon over a broad range of laser intensities, investigated by studying the time evolution of the ablation plume ejection, which, as measured by transmission of a probe beam, consists of a fast ejection phase followed by a delayed slow ejection phase. Experimental results indicate that different...

We present a new experimental platform for studies of turbulence and turbulent mixing in accelerating and rotating fluids. The technology is based on the ultra-high performance optical holographic digital data storage. The state-of-the-art electro-mechanical, electronic, and laser components allow for realization of turbulent flows with high Reynol...

In this paper, we report the effects of direct-write e-beam parameters on achieving sub-micron periodic domain structures in homoepitaxial liquid phase epitaxy (LPE) LiNbO3 thin films. We have studied the effects of the e-beam acceleration voltage, the areal dose, and the scanning speed on the domain structure regularity, and we have obtained optim...

By using the direct-write e-beam technique with liquid phase epitaxy LiNbO3 thin films, we have successfully produced sub-micron domain structures for achieving dynamically switchable filters in a periodically poled lithium niobate (PPLN) waveguide. The effects of direct-write e-beam parameters are investigated to achieve sub-micron periodic domain...

We have demonstrated sub-micron domain (∼200 nm) structures with a period ∼750 nm and ∼1.2 μm in liquid phase epitaxy (LPE) LiNbO3 films on congruent LiNbO3 substrates by using the direct-write e-beam domain engineering method. In comparison with single crystal congruent LiNbO3 (CLN) and stoichiometric LiNbO3 (SLN), we show that LPE LiNbO3 (LPE LN)...

Rear surface spallation of single-crystal silicon under 5‐ns laser pulse ablation at intensities of 0.6–60 GW/cm2 is studied through postablation examination of the ablated samples. The spallation threshold energy and the spallation depth’s dependences on the energy and target thickness are measured. From the linear relation between the spallation...

By using a direct-write e-beam technique with liquid phase epitaxy LiNbO3 thin films, we have successfully produced sub-micron domain structures for achieving dynamically switchable filters in a periodically poled lithium niobate (PPLN) waveguide. Sub-micron domain (~200 nm) structures with a period ~1.2 um are realized in liquid phase epitaxy LiNb...

By using the direct-write e-beam technique with liquid phase epitaxy LiNbO3 thin films, we have successfully produced sub-micron domain structures for achieving dynamically switchable filters in a periodically poled lithium niobate (PPLN) waveguide. The effects of direct-write e - beam parameters are investigated to achieve sub-micron periodic doma...

We report comparisons of high intensity laser-matter interactions in nanosecond regime with laser wavelength of 355, 532 and 1064nm. A probe beam transmission method is utilized in analyzing the time evolutions of the interactions. Experimental results are compared with theoretical estimations based on the delayed phase explosion model. Full-text a...

We describe the design and implementation of a high-data-rate high-capacity digital holographic storage disk system. Various system design trade-offs that affect density and data-rate performance are described and analyzed. In the demonstration system that we describe, high-density holographic recording is achieved by use of high-resolution short-f...

In this paper, we discuss fundamental issues underlying holographic data storage: grating formation, recording and readout of thick and thin holograms, multiplexing techniques, signal-to-noise ratio considerations, and readout techniques suitable for conventional, phase conjugate, and associative search data retrieval. Next, we consider holographic...

We present theoretical calculations and experimental measurements of silicon micromachining rates, efficiency of laser pulse utilization, and morphology changes under UV nanosecond pulses with intensities ranging from 0.5 GW/cm2 to 150 GW/cm2. Three distinct irradiance regimes are identified based on laser intensity. At low intensity, proper gas dy...

We demonstrate submicron ferroelectric domain engineering in liquid phase epitaxy (LPE) LiNbO3 thin films grown on LiNbO3 and LiTaO3 substrates using a direct-write electron beam poling for waveguide applications. LiNbO3 thin films of several-micron thickness were grown using a flux melt of 20 mol% LiNbO3-80 mol% LiVO3. To engineer domain structure...

We describe a three-dimensional theoretical model of holographic shift multiplexing in thin volumetric media in paraxial approximation. In the case of shift multiplexing with three-dimensional beams, additional cross talk is found and its origin is attributed to Bragg-matching synchronism which occurs when shift in both transverse dimensions (x and...

Hologram recording in photorefractive media is classically performed in the blue-green spectral range and suffers from optical erasure under continuous readout, unless a thermal fixing technique is applied. Gated optical holographic recording allows us to obtain high-diffraction efficiencies in the near InfraRed (IR) jointly with long-term storage....

© 2003 Optical Society of America

In digital holographic data storage data modulation coding, data interleaving, and error correction are usually implemented in addition to conventional holography and multiplexing. The performance of the holographic disk digital data storage system is determined by several major factors, most notably, by the optical parameters (such as the imaging...

We develop two different approaches to realize content-addressed or associative recall for phase-coded multiplexing, and present theoretical and experimental results of associate recall in phase-coded memory systems designed for digital data storage. Moreover, a comparison of the performance of associative recall in systems based on angular and pha...

Codoped lithium niobate of congruent and stoichiometric compositions had been successfully grown specifically for holographic data storage applications. The dopants we have selected are Mn and Ce and their role in the recording process is described. Growth methods, sample preparation, doping level measurements, holographic recording data as well as...

We present two different techniques on how to realize a content-addressed holographic memory when using phase-code multiplexing, relying on simple intensity measurements rather than phase distributions. Theoretical and experimental results of associative recall in a phase-coded system designed for digital data storage will be presented and compared...

The article focuses on storing data inside the volume of the recording medium, rather than on its surface, as in conventional optical and magnetic approaches. These systems deliver much higher data-transfer rates and access based on partial information. Holographic data storage records information in the form of volumetric gratings within the volum...

Holographic data storage records information in the form of volumetric gratings within the volume of the recording medium. In digital holographic storage information is typically encoded in the form of data pages, which includes modulation coding, data shuffling, and error correction. Selective properties of volumetric gratings allow for a multitud...

We describe a fully functional, hardware implemented, high data rate (1 Gbit/sec) high capacity digital holographic data storage photopolymer disk system. High density holographic recording is achieved using high-resolution short focal length optics and correlation shift multiplexing. Sustained data transfer rates as high as 10 Gbit/s in optical do...

Virtually all volume holographic recording materials require a fixing process to reduce or eliminate their sensitivity to light of the recording wavelength as they are being read out. This is true because illuminating the medium with light of the readout wavelength will ultimately either erase the recorded information, as in the case of photorefrac...

form only given.Volume holographic recording of information is an attractive solution for the next generation of digital storage, holding promise for systems with high density (/spl ges/10 Gbit/cm/sup 2/), and fast transfer rate (Gbit/sec). The performance of a holographic storage system is principally determined by the recording medium characteris...

Optically gated recording and nonvolatile readout in a digital volume holographic data storage system that uses a pair of mutually incoherent light sources during recording and only one for readout were demonstrated recently. This approach used stoichiometric lithium niobate, which after post-growth processing gave rise to an at least two orders of...

We demonstrate a novel apodization technique for holographic data storage using two-photon recording in stoichiometric lithium niobate. The gating light-intensity profile is used to achieve grating apodization inside the bulk of the crystal during recording in the transmission geometry. Experimental Bragg-selectivity curves and theoretical fits ind...

Digital holograms have been written in stoichiometric Pr:LiNbO(3) in a two-color recording scheme, demonstrating what is to our knowledge the first all-optical nondestructive readout of digital data. Using writing light at 800nm and gating light at 476 nm, we stored and retrieved 256-kbit digital data pages with a raw bit-error rate BER of <10(-4)...

Summary form only given. Photorefractive lithium niobate (LN) remains one of the most promising materials for holographic data storage applications. Some of the most important concerns in this field are the fixing of recorded holograms, as well as their strength and lifetime. It is well established that the ionic conductivity in as-grown LN crystal...

We show that the nonlinear index perturbation due to light-induced photovoltaic space-charge field in LiNbO3 can give rise to self-phase matching of second harmonic generation. Increase of the conversion efficiency is accompanied by formation of stationary and nonstationary patterns in the spatial structure of the generated second harmonic. The spa...

A study on holographic data storage in photorefractive crystals, focusing on LiNbO3 crystals, was presented. This work was different because it took advantage of the significant discrepancy between the transport time constants involved in typical crystals, particularly LiNbO3, thus simple analytic expressions for the time-dependent field in each of...

We study self-oscillation in a photorefractive double phase-conjugate mirror and show that it undergoes an order-disorder phase transition at a critical gain-threshold point. We present theoretical and experimental results on two key properties of this phase transition: critical slowing down and the characteristic order parameter. We show that the...

We model the double phase-conjugate mirror (DPCM) as a function of time, the average direction of propagation of the two beams forming the DPCM, and one transverse coordinate. Calculations show that the conjugation fidelity and reflectivity have different dependencies on the photorefractive coupling coefficient times length; the fidelity turns on a...

Sr(0.59)Ba(0.41)Nb(2)O(6) and Sr(0.75)Ba(0.25)Nb(2)O(6) exhibit an intensity-dependent absorption in the visible spectral range. We perform pump (green)-probe (red) measurements and find variation as high as 0.45 cm(-1) in the absorption coefficient, which depends significantly on the polarization of the probe light beam. Our results indicate a non...

Summary form only given. In conclusion, we present theoretical and experimental results that analyze the double phase conjugation process. We establish the existence of gain-threshold and point out the differences between conjugation fidelity and conjugation reflectivity. We study the oscillatory nature of the DPCM and predict the existence of crit...

Photorefractive (PR) strontium barium niobate (SBN) has been the subject of extensive research in recent years. Large PR nonlinearities and relatively fast response time at low power levels make this material a preferred candidate for a variety of applications such as optical data storage. Intensity dependent absorption and related phenomena were d...

We present an experimental study of the behavior of photorefractive double phase-conjugate mirrors that illustrates recent theoretical predictions. We observe a sharp fidelity threshold that significantly depends on the specific feature size in the input beams. Furthermore, we find that if the two input beams have unequal intensities the conjugatio...

We report measurements of the holographic diffraction efficiency (HDE) of single photorefractive gratings fixed by an externally applied voltage pulse in Sr 0.75 Ba 0.25 Nb 2 O 6 . The polarization grating HDE and decay rate are strongly dependent on the grating spacing and also depend on the intensity of the light beams during the recording and er...

We present a model describing the formation of a photorefractive grating in the presence of photorefractively inactive space‐charge modulation. The treatment is based on standard linearized Kukhtarevs equations. The model developed is applied to the interpretation of experimental results on electrical fixing in Sr 0.75 Ba 0.25 Nb 2 O 6 .

An investigation on electrical fixing of photorefractive holograms in title compound is reported. The novel ways of fixing holograms in the crystal are presented, that give improved performance, and show that holograms of images can be fixed and faithfully reproduced. Single gratings and images are recorded and fixed.

Photorefractive holograms stored in Sr(0.75)Ba(0.25)Nb(2)O(6) crystals are electrically fixed at room temperature. The fixed holograms can be read out directly or after a positive-voltage pulse is applied that can dramatically enhance the diffraction efficiency. Single gratings as well as images are recorded and fixed.

We report the experimental demonstration of electrical fixing of photorefractive holograms in SBN:75 crystals.