Ultra-Wideband Time-Stretched Digitizer

Research | Ultra-Wideband Time-Stretched Digitizer

With increasing bandwidth demands from internet backbones, optical links with 100 Gb/s and higher data rates per wavelength channel are being targeted. To meet these demands, spectrally efficient modulation formats are being developed. The receivers in such links will require very high speed and resolution analog-to-digital converters (ADCs), which are currently beyond the capability of present day electronics. High-bandwidth digitizers are also needed for defense applications such as radars, and in detection of ultrafast electromagnetic pulses. In science, such digitizers are central tools in particle accelerators or X-ray free electron laser systems as well as in time-resolved

fluorescence microscopy. The goal of this research is to use photonics to extend the capabilities of electronics to meet these demands. This is achieved by photonic time-stretch technology, which uses photonics to slow down electrical signals in time. Hence, an electronic digitizer that would have been too slow to capture the original electrical signal can now capture the stretched and slowed down signal. We have a world record for analog-to-digital conversion rate.

[1] S. Gupta and B. Jalali, “Time stretch enhanced recording oscilloscope,” Applied Physics Letters 94, 041105 (2009)

​[2] J. Chou, O. Boyraz, D. R. Solli, and B. Jalali, “Femtosecond real-time single-shot digitizer,” Applied Physics Letters 91, 161105 (2007)
[3] Y. Han, O. Boyraz, and B. Jalali, “Tera-sample-per-second real-time waveform digitizer,” Applied Physics Letters 87, 241116 (2005)
[4] F. Coppinger, A. S. Bhushan, and B. Jalali, “Photonic time stretch and its application to analog-to-digital conversion,” IEEE Transactions on Microwave Theory and Techniques 47, 1309 (1999)