Optical Communications in the mid-wave IR spectral band
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The mid-wave IR (MWIR) spectral band extending from 3 to 5 microns is considered to be a low loss atmospheric window. The MWIR wavelengths are eye safe and are attractive for several free-space applications including remote sensing of chemical and biological species, hard target imaging, range finding, target illumination, and free-space Communications. Due to the nature of light-matter interaction characteristics, MWIR wavelength based Systems can provide unique advantages over other spectral bands for these applications, The MWIR wavelengths are found to effectively penetrate natural and anthropogenic obscurants. Consequently, MWIR Systems offer increased range Performance at reduced power levels. Free-space, line-of-sight optical communication links for terrestrial as well as space based platforms using MWIR wavelengths can be designed to operate under low visibility conditions. Combined with high-bandwidth, eye-safe, covert and jam proof features, a MWIR wavelength based optical communication link could play a vital role in hostile environments.
A free-space optical communication link basically consists of a transmitter, a receiver and a scheme for directing the beam towards a target. Coherent radiation in the MWIR spectral band can be generated using various types of lasers and nonlinear optical devices. Traditional modulation techniques are applicable to these optical sources. Novel detector and other subcomponent technologies with enhanced characteristics for a MWIR based System are advancing. Depending on the transmitter beam characteristics, atmospheric conditions may adversely influence the beam propagation and thereby increasing the bit error rate. For satisfactory transmission over a given range, the influence of atmosphere on beam propagation has to be analyzed. In this chapter, salient features of atmospheric modeling required for wavelength selection and Performance prediction is presented. Potential optical sources and detectors for building a practical MWIR communication link are surveyed. As an illustration, the design configuration and experimental results of a recently demonstrated free-space, obscurant penetrating optical data communication link suitable for battlefield applications is discussed. In this case, the MWIR wavelength was derived using an all solid-state, compact, optical parametric oscillator device. With this device, weapon codes pertaining to small and large weapon platforms were transmitted over a range of 5 km. Furthermore, image transmission through light fog, accomplished using this hardware, is also presented.
Advances in source and detector technologies are contributing to the development of cost effective Systems compatible with various platforms requirements. In Coming years, MWIR wavelengths are anticipated to play a vital role in various human endeavors.
KeywordsOptical Parametric Oscillator Quantum Cascade Laser Scintillation Index Periodically Pole Lithium Niobate Atmospheric Transmission
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- 1.M.E. Thomas, D.D. Duncan, Atmospheric transmission, in Atmospheric Propagation of Radiation, vol. 2 of The Infrared & Electro-Optical Systems Handbook, edited by F. G. Smith, pp. 1–156, 1993.Google Scholar
- 2.L. Andrews, R. Phillips, Laser Beam Propagation through Random Media (SPIE Optical Engineering Press, Bellingham, WA, 1998).Google Scholar
- 4.J. Goodman, Introduction to Fourier Optics (McGraw-Hill, New York, 1996).Google Scholar
- 7.American National Standards for Safe Use of Lasers, ANSI ZI36.1-2000, published by American National Standards Institute, New York, 2000.Google Scholar
- 9.J. Hecht, The Laser Handbook (McGraw-Hill, New York, 1992).Google Scholar
- 10.Improved lead-salt lasers set power record, in Laser Focus World, vol. 33, p. 9, January 1997.Google Scholar
- 16.J. Schneider, C. Carbonnier, U.B. Unrau, Continuous wave über laser Operation at a wave-length of 3.9 micrometers, OS A TOPS on Advanced Solid-State Lasers, 1, 333–334 (1996).Google Scholar
- 17.R.C. Eckardt, L. Esterowitz, I. D. Abella, Multiwavelength mid-IR laser emission in Ho: YLF, paper FM5, Digest for Conference on Lasers and Electro-Optics, p. 160, 1982.Google Scholar
- 18.R.L. Byer, Optical parametric oscillators, in Quantum Electronics: A Treatise, edited by H. Rabin and C.L. Tang, pp. 587–701, 1975.Google Scholar
- 19.A. Yariv and P. Yeh, Optical Waves in Crystals (John Wiley & Sons, New York, 1984).Google Scholar
- 20.V.G. Dmitriev et. al., Handbook of Nonlinear Optical Crystals (Springer-Verlag, New York, 1991).Google Scholar
- 30.W. Koechner, Solid-state Laser Engineering, 4th ed. (Springer, New York, 1996).Google Scholar
- 31.Selected papers on Optical Parametric Oscillators and Amplifiers and Their Applications, edited by Jeffrey H. Hunt, SPIE Milestone Series, Vol. MS 140, Bellingham, WA, 1997.Google Scholar
- 32.SNLO nonlinear optics code available from A.V Smith Sandia National Laboratories, Al-buquerque, NM 87185-1423.Google Scholar
- 36.K. Kaufmann, Detectors cover the spectrum of instrument applications, in Laser Focus World, vol. 30, pp. 99–105, 1994.Google Scholar
- 37.Eltec Instruments, Inc., Passive Infrared Technology, High Megohm Resistors, Hybrid Electronics Product Catalog, Daytona Beach, FL.Google Scholar
- 38.Hamamatsu Corp., Optosemiconductors Condensed Catalog, Bridgewater, NJ.Google Scholar
- 41.Eye-Safe Multiple Integrated Laser Engagement System, Phase I Final Report CTI-TR-9708.Google Scholar
- 42.All Solid-State Mid-Wave Infrared Multiple Integrated Laser Engagement System (MILES), Phase II Final report CTI-TR-2001-27.Google Scholar
- 44.Quantitative Description of Obscuration Factors for Electro-Optical and Millimeter Wave Systems, DoD-HDBK-178 (ER), 1986.Google Scholar
- 46.R.M. Measures, Lasing Remote Sensing (John Wiley & Sons, New York, 1984).Google Scholar
- 47.Narasimha S. Prasad, Allen R. Geiger, Remote Sensing of Propane and Methane Using a Differential Absorption Lidar by topographic reflection, Opt. Eng., 35, 4 (1996).Google Scholar