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

Abstract

Abstract:Technologies for efficient generation and fast scanning of narrow free-space laser beams find major applications in three-dimensional (3D) imaging and mapping, like Lidar for remote sensing and navigation, and secure free-space optical communications. The ultimate goal for such a system is to reduce its size, weight, and power consumption, so that it can be mounted on, e.g. drones and autonomous cars. Moreover, beam scanning should ideally be done at video frame rates, something that is beyond the capabilities of current opto-mechanical systems. Photonic integrated circuit (PIC) technology holds the promise of achieving low-cost, compact, robust and energy-efficient complex optical systems. PICs integrate, for example, lasers, modulators, detectors, and filters on a single piece of semiconductor, typically silicon or indium phosphide, much like electronic integrated circuits. This technology is maturing fast, driven by highbandwidth communications applications, and mature fabrication facilities. State-of-the-art commercial PICs integrate hundreds of elements, and the integration of thousands of elements has been shown in the laboratory. Over the last few years, there has been a considerable research effort to integrate beam steering systems on a PIC, and various beam steering demonstrators based on optical phased arrays have been realized. Arrays of up to thousands of coherent emitters, including their phase and amplitude control, have been integrated, and various applications have been explored. In this review paper, I will present an overview of the state of the art of this technology and its opportunities, illustrated by recent breakthroughs.

Hybrid Integration of Solid-State Quantum Emitters on a Silicon Photonic Chip

“…It has a large refractive index that enables many photonic components to fit into a small device size. [15][16][17] Electrical contacts incorporated into the photonic structure can rapidly modulate and reconfigure these components by free-carrier injection on fast timescales. 18,19 Silicon is also compatible with standard CMOS fabrication methods that can combine electronics with photonics on a large scale.…”

“…18,19 Silicon is also compatible with standard CMOS fabrication methods that can combine electronics with photonics on a large scale. 15,16 For these reasons, silicon photonics can achieve the most complex integrated photonic structures to date composed of thousands of optical components in a single chip. 20,21 However, since silicon is also an indirect bandgap material with poor optical emission properties, it has not been possible to integrate efficient atom-like quantum emitters.…”

Opportunities for photonic integrated circuits in optical gas sensors

“…PICs combine several functionalities on a substrate, e.g. lasers, modulators, detectors and amplifiers [10]. The development in the field was mainly driven by telecommunications applications, and a trend similar to the development in micro-electronics was predicted and seems to hold [11,12].…”

“…Figure 2 shows the increase of complexity of some of those platforms over the last 30 years. The figure is adapted from [10], but we added two more data points corresponding to recent publications [13,14].…”

Picosecond optical pulse processing using a terahertz-bandwidth reconfigurable photonic integrated circuit

“…impulse responses and spectral responses. To date, a number of important functions have been demonstrated using such topologies, including delay lines [40][41][42], temporal waveform shapers [24,43], spectral filters [44][45][46][47][48][49][50][51], multi-port switches [52][53][54][55][56], Fourier transforms [23,45], correlators [57], beamformers [58][59][60][61], quantum processors [62,63] and mesh networks [64][65][66].…”