Abstract
We experimentally demonstrate an optics-based half-adder of two 4-phase-shift-keying (4-PSK) data channels using nonlinear wave mixing. The optics-based half-adder has two 4-ary phase-encoded inputs (i.e., SA and SB) and two phase-encoded outputs (i.e., Sum and Carry). The input quaternary base numbers {0,1,2,3} are represented by 4-PSK signals A and B with four phase levels. Along with the original signals A and B, the phase-conjugate signal copies A* and B*and phase-doubled signal copies A2 and B2 are also generated to form two signal groups SA(A, A*, A2) and SB(B, B*, B2). All of the above signals in the same signal group are (a) prepared in the electrical domain with a frequency spacing of Δf and (b) generated optically in the same IQ modulator. When combined with a pump laser, group SA mixes with group SB in a periodically poled lithium niobate nonlinear (PPLN) device. At the output of the PPLN device, both the Sum (A2B2) and the Carry (AB + A*B*) are simultaneously generated with four phase levels and two phase levels, respectively. In our experiment, the symbol rates can be varied between 5 Gbaud and 10 Gbaud. The experimental results show that (i) the measured conversion efficiency of two 5-Gbaud outputs is approximately −24 dB for Sum and approximately −20 dB for Carry, and (ii) the measured optical signal-to-noise ratio (OSNR) penalty of the 10-Gbaud Sum and Carry channels is <10 dB and <5 dB, compared with that of the 5-Gbaud channels at the BER of 3.8 × 10−3.
© 2023 Optica Publishing Group
Full Article | PDF ArticleMore Like This
Amir Minoofar, Narek Karapetyan, Ahmed Almaiman, Huibin Zhou, Hao Song, Kaiheng Zou, Wing Ko, Muralekrishnan Ramakrishnan, Murali Annavaram, Jonathan L. Habif, Moshe Tur, and Alan E. Willner
Opt. Lett. 48(17) 4617-4620 (2023)
Ahmed Almaiman, Morteza Ziyadi, Amirhossein Mohajerin-Ariaei, Yinwen Cao, Mohammad Reza Chitgarha, Peicheng Liao, Changjing Bao, Bishara Shamee, Nisar Ahmed, Fatemeh Alishahi, Ahmad Fallahpour, Youichi Akasaka, Jeng-Yuan Yang, Motoyoshi Sekiya, Joseph D. Touch, Moshe Tur, Carsten Langrock, Martin M. Fejer, and Alan E. Willner
Opt. Lett. 41(12) 2680-2683 (2016)
Kaiheng Zou, Peicheng Liao, Huibin Zhou, Ahmad Fallahpour, Amir Minoofar, Ahmed Almaiman, Fatemeh Alishahi, Moshe Tur, and Alan E. Willner
Opt. Lett. 46(6) 1325-1328 (2021)