Existing satellite laser communications systems utilize narrow bandwidth (<2 nanometer) sources and modulation techniques, such as Binary Phase Shift Keying (BPSK) for the extant European Data Relay System (EDRS), and Differential Phase Shift Keying (DPSK) for NASA's Laser Communication Relay Demonstration (LCRD). These systems rely on the speed of phase shifting near infrared telecommunications electronics for data encoding, not the available bandwidth of the source.
A paper entitled “Suppression of intensity fluctuations in free space high-speed optical communication based on spectral encoding of a partially coherent beam” in Science Direct, Optics Communications 280, August 2007, pages 264-270, by Gennady P. Berman et al. describes a free space, high-speed (Gbps) optical communication system based on spectral encoding of radiation from a broadband pulsed laser. This paper describes that scintillations can be suppressed by orders of magnitude for distances of more than 10 km with the use of partially coherent laser beams and a relatively slow photosensor.
A paper entitled “High Data-rate, Free-space Laser Communication Based on Frequency Encoding of a Partially Coherent Beam” by Gennady P. Berman et al., Los Alamos National Laboratory, describes a free-space, high-speed optical communication (FSOC) system based on spectral encoding of radiation from a broadband, pulsed laser. This paper proposes to extend a technique of scintillation suppression, based on time averaging of a partially coherent beam, to a gigabit data rate FSOC.
A paper entitled “Development of a terawatt coherent white light lidar system and applications to environmental studies” by Chihiro Yamanka et al., Multispectral, Hyperspectral, and Ultraspectral Remote Sensing Technology, Techniques, and Applications II, Proc. Of SPIE Vol. 7149, 71490Z, 2008, describes a white light lidar system which uses an intense femtosecond laser pulse and self-trapping in atmospheric-pressure of Kr gas to obtain multi-wavelength backscattering and depolarization profiles from aerosols and clouds.