Phase customization in photonic integrated circuits with trimmed waveguides

Abstract

Accurate photon phase control on a chip is essential to improve the expandability and stability of photonic integrated circuits (PICs). Here, we propose a novel, to the best of our knowledge, on-chip static phase control method in which a modified line is added close to the normal waveguide with a lower-energy laser. By controlling the laser energy and the position and length of the modified line, the optical phase can be precisely controlled with low loss and a three-dimensional (3D) path. Customizable phase modulation ranging from 0 to 2π is performed with a precision of λ/70 in a Mach–Zehnder interferometer. The proposed method can customize high-precision control phases without changing the waveguide’s original spatial path, which is expected to control the phase and solve the phase error correction problem during processing of large-scale 3D-path PICs.

All-optical logic operations based on silicon-on-insulator waveguides

“…Researchers are currently concentrating on on-chip optical phase compensation and reconfiguration employing unique techniques that can be separated into dynamic and static phase control schemes. 24,25 A thermooptic phase shifter is employed to regulate the phase between two distinct waveguides on the chip. Over one of the waveguides where a current can flow, a tiny nickel-chromium electrode is directly deposited.…”

“…The modified line can change the effective refractive index of the waveguide by maintaining its single-mode property. 25 Conversely, destructive interference scatters the incident beams and yields a "0" output when the waveguide and incident beams are out of phase. Typically, the CR is defined as CRðdBÞ ¼ 10 ln½P 1 mean ∕P 0 mean 14,21 takes into account the peak power of all outputs bits (i.e., P 1 mean and P 0 mean ), while other metrics, such as the extinction ratio, only take into account the peak power of the minimum and maximum outputs "1" and "0," respectively.…”

“…The incident beams must satisfy the phase-matching requirements for T to be maximized. Researchers are currently concentrating on on-chip optical phase compensation and reconfiguration employing unique techniques that can be separated into dynamic and static phase control schemes 24 , 25 . A thermooptic phase shifter is employed to regulate the phase between two distinct waveguides on the chip.…”

“…By keeping its single-mode feature, the changed line can change the waveguide’s effective refractive index. The modified line can change the effective refractive index of the waveguide by maintaining its single-mode property 25 . Conversely, destructive interference scatters the incident beams and yields a “0” output when the waveguide and incident beams are out of phase.…”

All-Optical XOR, AND, OR, NOT, NOR, NAND, and XNOR Logic Operations Based on M-Shaped Silicon Waveguides at 1.55 μm

“…The outcomes of the simulations are captured by setting FDTD monitors, i.e., , where I out is the intensity at the output port (i.e., port 4), and , which is the sum of the intensities at three input ports [ 26 , 27 , 28 , 29 , 30 , 31 ]. The value of 0.2 is assigned to the normalized threshold transmission (T th ), which is the minimum normalized power required to generate T. To optimize T, the incident beams have to meet suitable phase-matching conditions [ 44 , 45 ]. From a logical perspective, port 4 produces an output of ‘1’ only if T > T th and ‘0’ if T ≤ T th .…”