Minoofar Amir, Karapetyan Narek, Almaiman Ahmed, Zhou Huibin, Song Hao, Zou Kaiheng, Ko Wing, Ramakrishnan Muralekrishnan, Annavaram Murali, Habif Jonathan L, Tur Moshe, Willner Alan E
Opt Lett. 2023 Sep 1;48(17):4617-4620. doi: 10.1364/OL.496438.
Networks can play a key role in high-speed and reconfigurable arithmetic computing. However, two performance bottlenecks may arise when: (i) relying solely on electronics to handle computation for multiple data channels at high data rates, and (ii) the data streams input to a processing node (PN) are transmitted as phase-encoded signals over an optical network. We experimentally demonstrate the operation of optically-assisted reconfigurable average of two 4-phase-encoded data channels at 10- and 20-Gbaud rates. Our input signals are two streams of 2-bit numbers representing a binary floating-point format, and the operation results in 7-phase-encoded output signals represented by 3-bit numbers. The average operation is achieved in three stages: (1) phase encoding and division-using an optical modulator to encode the data streams; (2) summation-using a highly nonlinear fiber (HNLF); and (3) multicast-using a periodically poled lithium niobate (PPLN) waveguide to multicast back the result into the original signal wavelengths. The experimental results validate the concept, and the measured penalties indicate that: (i) the error vector magnitudes (EVMs) of optical signals increase at each stage and reach ∼18-21% for the final multicast results, and (ii) compared to the inputs, the optical signal-to-noise ratio (OSNR) penalty of output is ∼6.7 dB for the 10-Gbaud rate and ∼6.9 dB for the 20-Gbaud rate at a bit error rate (BER) of 3.8e-3.
网络在高速和可重构算术计算中可以发挥关键作用。然而，当出现以下两种情况时可能会出现两个性能瓶颈：（i）仅依靠电子设备以高数据速率处理多个数据通道的计算，以及（ii）输入到处理节点（PN）的数据流作为相位编码信号通过光网络进行传输。我们通过实验演示了在10和20 Gbaud速率下对两个4相编码数据通道进行光辅助可重构平均运算的操作。我们的输入信号是表示二进制浮点格式的两个2位数流，运算结果是由3位数表示的7相编码输出信号。平均运算分三个阶段实现：（1）相位编码和除法——使用光调制器对数据流进行编码；（2）求和——使用高非线性光纤（HNLF）；（3）多播——使用周期性极化铌酸锂（PPLN）波导将结果多播回原始信号波长。实验结果验证了这一概念，测量得到的代价表明：（i）光信号的误差矢量幅度（EVM）在每个阶段都会增加，最终多播结果的EVM达到约18 - 21%，并且（ii）与输入相比，在误码率（BER）为3.8e - 3时，10 Gbaud速率下输出的光信噪比（OSNR）代价约为6.7 dB，20 Gbaud速率下约为6.9 dB。
