Abstract

Optical sampling is performed mostly in either time or frequency domain. In the former approach, sampling points are temporally taken by photo-mixing of received signals with locally generated ultrashort pulses. In the latter approach, the received signal is spectrally sliced and decomposed, which are taken as sampling points in the frequency domain. In this paper, as an alternative way, we propose and investigate an optical sampling technique called optical time-frequency-domain sampling, in which sampling points are taken in the time-frequency domain in an optoelectronic manner, by means of optoelectronic coherent matched detectors. Using this technique, it is possible to demultiplex and detect subchannels of ultrawideband multi-carrier signals at e.g. 100, 400 Gb/s, 1 Tb/s or higher, without relying on either ultrashort pulses or high-resolution optical filters necessary in the conventional time- or frequency-domain sampling approaches. Moreover, in this paper, we propose and demonstrate a loop-assisted coherent matched detector that simply and practically extends the time-frequency sampling to parallel sampling configuration just using a single coherent matched detector. Provided are some experimental proof focusing on demultiplexing and detection of orthogonal time-frequency-domain multipelxed (OTFDM) signals, a sort of ultrawideband multicarrier signals. All subchannels of 160-Gb/s QPSK-OTFDM signals are simultaneously detected and measured with the loop-assisted coherent matched detector employing a single set of low-speed 10-Gbaud photo-receivers.

© 2016 OAPA

Orthogonal time-frequency domain multiplexing with multilevel signaling

Takahide Sakamoto
Opt. Express 22(1) 773-781 (2014)

Multi-tone parallel coherent matched detection for demultiplexing of superchannels

Takahide Sakamoto, Guo-Wei Lu, and Tetsuya Kawanishi
Opt. Express 21(16) 18602-18610 (2013)

Real-time coherent detection of phase modulated ultrashort pulses after time-to-space conversion and spatial demultiplexing

Dror Shayovitz, Harald Herrmann, Wolfgang Sohler, Raimund Ricken, Christine Silberhorn, and Dan M. Marom
Opt. Express 22(25) 31138-31145 (2014)

High-performance TDM demultiplexing of coherent Nyquist pulses using time-domain orthogonality

Koudai Harako, David Odeke Otuya, Keisuke Kasai, Toshihiko Hirooka, and Masataka Nakazawa
Opt. Express 22(24) 29456-29464 (2014)

Hybrid OFDM receiver assisted by a variable frequency comb

Huan Hu and Stojan Radic
Opt. Express 28(4) 5658-5668 (2020)