On the fabrication of three-dimensional silicon-on-insulator based optical phased array for agile and large angle laser beam steering systems

Abstract

In this article, the authors present and discuss the fabrication of three-dimensional ͑3D͒ optical phased array ͑OPA͒ devices for large angle, two-dimensional optical beam steering. Fabrication of a single layer ͑one-dimensional͒ OPA prototype for one-dimensional beam steering on silicon nanomembrane is presented. The authors present different approaches, such as nanoimprint lithography, optical lithography, and self-aligned patterning of multibonded silicon-on-insulator wafers, for the realization of 3D OPA devices in particular and 3D photonic circuits in general. At the end, the authors discuss the challenges and potential solutions.

High-efficiency end-fire 3D optical phased array based on a multi-layer Si3N4/SiO2 platform

“…First, the method proposed in [12] can be utilized in this fabrication, the challenge in this method will be the control on the planarization step, this step will influence the thickness of the sandwiched SiO 2 layer, while the precise control of this thickness is crucial in this structure. Second, thanks to the identical patterns on each Si 3 N 4 layer, it is possible to utilize the self-aligning method proposed in [15]. The fact that Si 3 N 4 and SiO 2 have a low etching selectivity between each but both have a high selectivity against Si also can help on this method: the selectivity difference offers a possibility to etch down multiple layers of Si 3 N 4 and SiO 2 within the same etching step where a Si is used as the mask.…”

“…Several works have been attempted to address the relatively low efficiency challenge [11][12][13][14][15][16]. In [11], a structure configuration to emit light from the edge of the chip is utilized.…”

Highly integrated optical phased arrays: photonic integrated circuits for optical beam shaping and beam steering

“…To achieve 2D beam steering, a stack of 1D silicon photonic PICs was suggested in Ref. [15]. This approach is shown schematically in Figure 4.…”

Reconfigurable integrated optoelectronics

“…To illuminate that point, let us imagine that LSI is here today-imagine that we are given a chip that contains 10,000 nanophotonic components of our choosing. Then two questions arise immediately: (1) What is the specific function of the chip-system? (2) What is the specific architecture that will be employed to actualize the system?…”

“…That MURI team used two bonded photonic layers containing phase shifters and time delays to steer on optical beam in one dimension [1].…”