High-performance optical code generation and recognition by use of a 511-chip, 640-Gchip/s phase-shifted superstructured fiber Bragg grating

Abstract

The generation and recognition of a record-length 511-chip optical code is experimentally demonstrated by use of a superstructured fiber Bragg grating (SSFBG) with a chip rate of 640 Gchips/s. Very high reflectivity (92%) is achieved with high-quality correlation properties. The temperature deviation tolerance is approximately +/- 0.3 degrees C, which is within the package's temperature stability range (+/- 0.1 degrees C). Experimental results show good agreement with the theory. They indicate the SSFBG's potential for processing a long optical code with an ultrahigh chip rate, which could significantly improve the system's performance.

Advances in Fibre Based Pulse Shaping Technology and its Applications in Optical Communications

“…In terms of the technology, SSFBG encoders with both amplitude and up to 4-level phase shift keying have been demonstrated, with code length of up to 511 Chips (at chip rates of up to 640 GChip/s) [9]. Current work is now focused more on assessing the system performance of such devices.…”

Multipolar inserting zeros code and its application in optical code division multiple access systems

“…1͒ to 127, 2 255, 3 up to 511. 4 Because these encoders use bipolar code, all of them are coded with a Gold sequence, which has been thoroughly studied. However, from research, we find that this code is not the best choice for SSFBG encoding.…”

10-user, truly-asynchronous OCDMA experiment with 511-chip SSFBG en/decoder and SC-based optical thresholder

“…In coherent OCDMA, encoding and decoding are based on optical field amplitude instead of power intensity. The coding can be either direct time-spreading the ultra-short optical pulse using PLC [2] and SSFBG [7][8] or spectral phase-encoded timespreading using SLPM [3][4][5][6].…”

“…A theoretical analysis has predicted that to support up to K=10 error free (BER<10 -9 ) transmission with chip-rate detection, ξ should be lower than -27 dB [1]. Phase-shifted SSFBG en/decoder is one desired candidate that has the capability to process OC as long as 511-chip with chip-rate as high as 640 Gchip/s [8] enabling us to challenge a truly-asynchronous OCDMA. In theory, about 7 active users can be supported for error free transmission at 1.25 Gbit/s with data-rate detection, while by employing optical thresholding to reject the MAI, the number of users could be doubled [1].…”

“…In coherent OCDMA, encoding and decoding are based on optical field amplitude instead of power intensity. The coding can be either direct time-spreading the ultra-short optical pulse using PLC [2] and SSFBG [7][8] or spectral phase-encoded timespreading using SLPM [3][4][5][6].In a common multi-user OCDMA network, multiple access interference (MAI) noise is the main issue [1][2][3][4][5][6][7]. The MAI could be suppressed effectively by employing time gating [2] or optical thresholding techniques [3][4][5][6].…”