All-optical phase-controlled phase modulators

In this study, we aim to develop an all-optical, phase-controlled modulator composed of lasers, optical directional couplers, optical amplifiers, and phase shifters. By employing a two-layer multilayer perceptron with matrix inversion, we determine the coupling ratios of the directional couplers and the phase delays of the phase shifters. Two types of all-optical phase-controlled phase modulators are designed. For the first type, the lag of the phase of the output light is sinusoidal with respect to the phase of the control light. For the second type, the phase of the output light is lagging linearly as the phase of the control light is leading. The standard error of the phase difference between the output light of the system and the target sinusoidal/linear output light could be as low as 1.56°. The standard error of the power of the output light for the control light with different phases could be as low as 3.7%. For the sinusoidal case, the device could serve as the nonlinear activation function, which is required for neurons in a photonic neuromorphic computing system.