Programmable photonic circuits

Abstract

The growing maturity of integrated photonic technology makes it possible to build increasingly large and complex photonic circuits on the surface of a chip. Today, most of these circuits are designed for a specific application. However, the increase in complexity creates an opportunity for a generation of photonic circuits that can be programmed in software for a wide variety of functions through a mesh of on-chip waveguides, tunable beam couplers and optical phase shifters. Here we discuss the state of this emerging technology, not just the recent developments in photonic building blocks and circuit architectures, but also the higher levels in the technology stack for the electronic control and programming strategies. We also cover the various possible applications in linear matrix operations, quantum information processing and microwave photonics and examine how these generic chips can accelerate the development of future photonic circuits by providing a higher-level platform for prototyping novel optical functionalities without the need for custom chip fabrication.

Photonic circuits written by femtosecond laser in glass: improved fabrication and recent progress in photonic devices

“…Next, combining writing structures (e.g., WGs and nanogratings) with chemical etching and metal deposition will be an important step to construct photonic integrated devices, which also provides the possibility of realizing thermo-optic or electro-optical control over device functionality. 4,167,168 Furthermore, for the photonic integrated circuit devices, reducing the coupling loss between the WGs and other optical components, such as optical fibers, is also important, which can be achieved by modulating the refractive index and size of WGs. For example, temperature gradient-assisted fs laser writing offers a promising technique to tune the size of WGs and reduce the coupling loss significantly.…”

“…Typically, the 3D designability gives WGs written by fs lasers superiority compared with the traditional 2D planar dielectric WGs. 4 Recently, integrated WGs with low power reconfigurability and reduced crosstalk have been produced by FLDW, and thermal phase shifting has been demonstrated, which indicates a very simple method for dynamic reconfiguration of the WGs. 168,170 These pave the way toward programmable photonic circuits, thus opening exciting perspectives in integrated photonics.…”

“…Photonic integrated circuits have shown the potential to allow integrating passive and active optical components on one chip in a scalable manner and have been identified to support a plethora of applications, such as data communication, sensing, astrophotonics, quantum information processing, and national security. [1][2][3][4] Photonic circuits are indispensable components in modern optical communication networks and lie at the heart of integrated photonic devices. Currently, to this end, one of the biggest challenges in integrated photonics is establishing a general and flexible method to produce photonic circuits with low loss, high integration density, and high tunability.…”

Graphene Oxide for Integrated Photonics and Flat Optics

“…Integrated platforms, particularly those compatible with the well‐developed complementary metal–oxide–semiconductor (CMOS) fabrication technology, such as silicon, silicon nitride (SiN), and doped silica, [ 12–14 ] have been widely exploited to implement integrated devices for many applications including telecommunications, IT services, displays, astronomy, sensing, and many others. [ 15–18 ] Integrating 2D materials into these platforms offers the best of both worlds: not only does it benefit in terms of compact device footprint, high stability, and mass producibility, but it also enables new capabilities and significantly improves the device performance by exploiting the superior material properties of 2D materials.…”

Up‐And‐Coming Advances in Optical and Microwave Nonreciprocity: From Classical to Quantum Realm

“…This effect requires ferrite materials (ferrites, such as yttrium iron garnet [YIG] and materials composed of iron oxides and other elements [Al, Co, Mn, Ni]) with static magnetic field bias. These devices are expensive, hard to tune, bulky, and incompatible with planar technologies like silicon‐based integrated circuits [ 12 ] and transmission‐line quantum circuits [ 13,14 ] that power the wireless and computing revolutions. Also, ferrite materials suffer from strong dissipative losses interfering with their use, especially in optics.…”