Development of radar pulse compression techniques using. Our ultraclear transmissive gratings have the highest efficiency on the market, with virtually no ghosting or scatter. Selfphase modulation and optical pulse compression influenced by. Compression of amplified chirped optical pulses sciencedirect. The use of selfphase modulation in a singlemode fiber to chirp an optical pulse, which is then compressed with a gratingpair compressor, has been shown to be a practical technique for the production of optical pulses at least as short as 30 fsec.
Indeed, we see in section 4 that the transverse compression of 30 kev electrons is a relatively weak function of t. Typical output from a pulsecompression filter the output of the pulsecompression filter forms the input into the detector section of the pulsecompression radar. The open access journal for physics new jou rnal of ph ys ics selfcompression of optical laser pulses by. Pulse compression radar is the practical implementation of a matchedfilter system. Kaiser is a pioneer in the use of vph gratings in ultrafast lasers with some of our earliest pulse compression gratings being designed for the center for ultrafast optical science located at the university of michigan and delivered in 1995. Ultra short optical pulse generation using electrooptic mach. Pedestal free pulse compression of chirped optical solitons. With a simple model, scaling laws are obtained for selfcompression in the limit of a large soliton number.
It is straightforward to estimate the effect on the pulse duration of a transformlimited input pulse no chirp. The stretched pulse is amplified and then compressed by a double grating compressor 3. Find out information about opticalpulse compression. Introduction to exploit the ultra wide bandwidth of optical fiber which. As femtosecond laser systems advance to everincreasing energy levels, demands on the energypower handling capabilities of pulse compression gratings increase. The pulse is linearly chirped in the fiber by the com bination of group velocity dispersion and selfphase modulation 2. Volume 56, number 3 optics communications 1 december 1985 compression of amplified chirped optical pulses donna strickland and gerard mourou l. Pulse compression gratings kaiser optical systems, inc. In most cases, this leads to chirped pulses, often with a duration which is even larger than the original pulse duration. Optical pulse compression and its effects using fiber bragg grating manoj divagar.
The fiber output pulses were then compressed to 450. The shortening of the duration of an optical pulse by techniques similar to those used in chirp radar, in which a frequency sweep is imposed on the pulse. Volume 56, number 3 optics communications 1 december 1985 compression of amplified chirped optical pulses donna strickland and gerard mourou t,ohorurorv or lu. The ideal device for carrying out this program has not been developed. Matched filtering algorithm for pulse compression radar. Tutorial this is a brief tutorial on prism and multipleprism pulse compression, and compressors, provided from a historical perspective. Pedestal free pulse compression of chirped optical solitons k.
Mar 15, 2012 soliton pulse compression and adiabatic pulse compression techniques are most commonly used ones for the compression process. Gratings for laser pulse compression wasatch photonics enhanced volume phase holographic vph gratings are exceptional for pulse compression and pulse stretching of high power ultrafast lasers. Optical pulse compression in fiber bragg gratings eprints soton. Singlediffractiongrating and grism pulse compressors vikrant chauhan, pamela bowlan, jacob cohen, and rick trebino school of physics, georgia institute of. Pulses as short as 5 fs were generated at repetition rates up to 1 mhz. Pdf design rules of optical pulse compression using fiberfiber.
Unfortunately, utilizing short pulses decreases the average transmitted power, which can hinder the radars normal modes of operation, particularly for multifunction and surv eillance radars. Pulse compression allows one to generate pulses of long duration minimizing damage problems and subsequently compress optical pulses to achieve the short pulse duration required for specific applications. Index termsnonlinear optics, optical pulse compression, ultrafast. Pulse compression is a signal processing technique commonly used by radar, sonar and echography to increase the range resolution as well as the signal to noise ratio. Taraprasad chattopadhyay department of physics visvabharati university santiniketan, west bengal, india. Alloptical threedimensional electron pulse compression. Highpower femtosecond optical pulse compression by using spatial solitons d. The pulses were frequency broadened and linearly chirped by the combined action of self. Osa optical pulse compression to 5 fs at a 1mhz repetition. A modification to this is the softknee compressor where the ratio increases progressively as the signal approaches the threshold, the end result being a less assertive, less obtrusive form of compression. Opticalpulse compression article about opticalpulse. Typical output from a pulse compression filter the output of the pulse compression filter forms the input into the detector section of the pulse compression radar. This scheme resembles that of an optical pulse compressor introduced by treacy 3 see figure 1b and widely used in laser optics.
This is achieved by modulating the transmitted pulse and then correlating the received signal with the transmitted pulse. Singlediffractiongrating and grism pulse compressors. Rp photonics encyclopedia pulse compression, shortening. Leaird bellcore, 331 newman springs road, red bank, new jersey 07701 received may 1, 1991 we demonstrate a novel pulsecompression technique. Highpower femtosecond optical pulse compression by using. We report the first experimental demonstration of the optical pushbroom a novel type of all optical pulse compression.
So we invented a singleprism pulse compressor akturk, et al. Pdf incoherent optical control of pulse propagation and. Linear compression of chirped pulses in optical fibre with large step. Pump pulse optical pulse group delay pulse compression short pulse duration. The pulses were frequency broadened and linearly chirped by the combined action of selfphase modulation and group velocity dispersion during passage through a 30m singlemode optical fiber. The pulse compression aspect of matched filtering can be seen in the example of fig. Additional experimental developments include a prismpair pulse compressor and a sixprism pulse compressor for semiconductor lasers.
The gratings have 1700 qmm groove spacing and are used in near littrow condition. The grating spacing was optimized for maximum compression of the pulses directly from the fiber. Taraprasad chattopadhyay department of physics visva. Swamp optics tutorial pulse compression recall that different colors propagate at different velocities so that, after passing through the material, different colors experience different delays, a ubiquitous effect called groupdelay dispersion gdd. Wai c a photonics division, department of physics, school of advanced sciences, vit university, vellore 632 014, tamil nadu, india. We discuss the design constraints for tapered pcfs used for adiabatic soliton compression and demonstrate over 15 times compression of pulses from over 830 fs. We report the results of a theoretical analysis of this process. Wai3 1photonics division, department of physics, school of advanced sciences, vit university. In a first step, the optical bandwidth is increased, typically with a nonlinear interaction such as selfphase modulation.
The rp photonics buyers guide contains 20 suppliers for pulse compressors. There seems to be a lot of mystique surrounding them, yet no one really seems to know why. Optical pulse compression in dispersion decreasing photonic crystal. An efficient time lens for optical pulse compression. In soliton pulse compression, the compressed pulses suffer from significant pedestal generation, leading to nonlinear interactions between neighboring solitons. Prismatic pulse compressors for femtosecond, and ultrafast tunable lasers, were first introduced, via a singleprism configuration, in 1983 by dietel et al. Ilayaraja abstract the optical pulse compression is analyzed by nlse using fiber bragg grating fbg with the help of second order dispersion. Pdf linear optical pulse compression based on temporal zone. Pulse stretching and compressing using grating pairs. Use for stretching or compressing of pulses stretcher. In the optical pushbroom high intensity pump pulses, tuned well away from the resonance of a bragg grating, modify the transmission of a weak probe tuned near to the gratings photonic bandgap. The amplified pulse is transmitted through the ar coated window to a double pass of a double grating compressor. While gdd tuning in a prism compressor can occur via simple prism translation or more complex variation in the prism separations, in grating or grism compressors, gdd adjustment requires the more complex variation in the separations between the. Chapter 5 pulse compression range resolution for a given radar can be significantly improved by using very short pulses.
Pulsecompression radar is the practical implementation of a matchedfilter system. Pulse compression techniques are used in radar systems to avail the bene. To satisfy the conditions t 0 t sat pulse with t 0 15 ps with t 0 t sat 0. The pulsecompression filter matched filter is simply looking for a strong correlation between what was transmitted and what was received. Pulse compression method for radar signal processing. Pulse compression allows one to generate pulses of long duration minimizing damage problems and subsequently compress optical. We report on the characterization and compression of the whitelight continuum produced by injection of a fs pulse from a cavitydumped selfmodelocked ti. Singlediffractiongrating and grism pulse compressors vikrant chauhan, pamela bowlan, jacob cohen, and rick trebino school of physics, georgia institute of technology, 837 state street, atlanta, georgia 30332 usa. Numerical results are presented for the achievable compression and compressed.
Leaird bellcore, 331 newman springs road, red bank, new jersey 07701 received may 1, 1991 we demonstrate a novel pulse compression technique that uses the selfconfinement of twodimensional spatial. The analogy between optical pulse compression and optical. Selfcompression of optical laser pulses by filamentation. Radar pulse compression chris allen june 17, 2004 outline why is pulse compression needed. The sy stem scheme is the sam e as the one shown in fig. Prismatic pulse compression was first introduced, using a single prism, in 1983 by dietel et al. Numerical results for gaussian and hyperbolicsecant initial pulse shapes and various initial amplitudes are used to verify the approximate analytic result and to determine accurate scaling constants. Pulse compression using optical fibers springerlink. Pulse compression an overview sciencedirect topics. Request pdf tunable alloptical pulse compression and stretching via doublet brillouin gain lines in an optical fiber we demonstrate tunable. Tunable alloptical pulse compression and stretching via doublet.
Basic principal of pulse compression 317 pulse compression radars transmit relatively long pulses with modulation and process the radar echo into very short pulses compressed. Gratings for laser pulse compression wasatch photonics. The pulse compression filter matched filter is simply looking for a strong correlation between what was transmitted and what was received. Intense stimulated raman scattering preferentially depletes and steepens the leading edge of 1. Balant, optical pulse compression based on enhanced. As seen in the upper figure, the measured pulse is a 1s long, 100hz wide lfm waveform only the real part of the complex basebanded signal is shown at an snr of. Optical pulse compression and its effects using fiber bragg.
For wavelengths less than those used in telecommunications about 1. All optical threedimensional electron pulse compression view the table of contents for this issue, or go to the journal homepage for more home search collections journals about contact us my iopscience. One can view the transmitted pulse as being composed of a series of very short subpulses duty is 100%, where the width of each subpulse is equal to the desired com. Find out information about optical pulse compression. The interest in using large lasers to achieve a very short and intense pulse for generating fusion plasma has provided a strong impetus to reexamine the possibilities of optical pulse compression at high energy. In these techniques a long duration pulse is used which is either phase or frequency modulated before transmission and the received signal. The reflected radar signal is corrupted by additive white gaussian noise awgn from the transmission channel.
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