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quantum limits of space-to-ground optical communicationsFor a pure loss channel, the ultimate capacity can be achieved with classical coherent states (i.e., ideal laser light): (1) Capacity-achieving receiver (measurement) is yet to be determined. (2) Heterodyne detection approaches the ultimate capacity at high mean photon numbers. (3) Photon-counting approaches the ultimate capacity at low mean photon numbers. A number of current technology limits drive the achievable performance of free-space communication links. Approaching fundamental limits in the bandwidth-limited regime: (1) Heterodyne detection with high-order coherent-state modulation approaches ultimate limits. SOA improvements to laser phase noise, adaptive optics systems for atmospheric transmission would help. (2) High-order intensity modulation and photon-counting can approach heterodyne detection within approximately a factor of 2. This may have advantages over coherent detection in the presence of turbulence. Approaching fundamental limits in the photon-limited regime (1) Low-duty cycle binary coherent-state modulation (OOK, PPM) approaches ultimate limits. SOA improvements to laser extinction ratio, receiver dark noise, jitter, and blocking would help. (2) In some link geometries (near field links) number-state transmission could improve over coherent-state transmission
Document ID
20130001815
Document Type
Presentation
External Source(s)
Authors
Hemmati, H.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Dolinar, S.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Date Acquired
August 27, 2013
Publication Date
May 8, 2012
Subject Category
Communications and Radar
Meeting Information
IEEE 2012 Conference on Lasers and Electroptics (CLEO)(San Jose, CA)
Distribution Limits
Public
Copyright
Other
Keywords
laser communications
optical communications
quantum limits

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