Chip-Scale Continuously Tunable Optical Orbital Angular Momentum Generator

TL;DR

This paper presents a compact silicon photonic integrated circuit capable of continuously tuning the orbital angular momentum (OAM) of light, enabling adjustable OAM states for advanced optical applications.

Contribution

A novel integrated silicon photonic device that generates and continuously tunes optical OAM states from a single electrical input, including non-integer values.

Findings

Demonstrated continuous tuning of OAM states.

Achieved compatibility with CMOS fabrication processes.

Potential for integration into large-scale photonic systems.

Abstract

Light carrying orbital angular momentum (OAM) has potential to impact a wide variety of applications ranging from optical communications to quantum information and optical forces for the excitation and manipulation of atoms, molecules, and micro-particles. The unique advantage of utilizing OAM in these applications relies, to a large extent, on the use of multiple different OAM states. Therefore, it is desirable to have a device that is able to gen- erate light with freely adjustable OAM states in an integrated form for large- scale integration. We propose and demonstrate a compact silicon photonic integrated circuit to generate a free-space optical beam with OAM state con- tinuously tuned from a single electrical input signal, realizing both integer and non-integer OAM states. The compactness and flexibility of the device and its compatibility with complementary metal-oxide-semiconductor (CMOS) pro- cessing hold promise for integration with other silicon photonic components for wide-ranging applications.