Pulse position modulation (PPM) is the preferred signaling format for deep space optical communications. Its high peak to average power ratio easily supports efficient forward error correction codes that operate within one dB of capacity at efficiencies better than one bit per detected photon when using photon counting detectors. Sub-100 picosecond slot widths are desired for efficient gigabit/second data links, but slot widths are limited by the jitter of available single photon detectors and laser modulators. Presently, the slot width must be larger than the receiver detector jitter and the transmitter modulator transition times. We show techniques whereby the slot time can be reduced, such that the jitter limitation is no longer the slot width but rather the PPM symbol duration.© (2008) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.