An InP-based vortex beam emitter with monolithically integrated laser

Abstract

Semiconductor devices capable of generating a vortex beam with a specific orbital angular momentum (OAM) order are highly attractive for applications ranging from nanoparticle manipulation, imaging and microscopy to fiber and quantum communications. In this work, an electrically pumped integrated OAM emitter operating at telecom wavelengths is fabricated by monolithically integrating an optical vortex emitter with a distributed feedback laser on the same InGaAsP/InP epitaxial wafer. A single-step dry-etching process is adopted to complete the OAM emitter, equipped with specially designed top gratings. The vortex beam emitted by the integrated device is captured and its OAM mode purity characterized. The integrated OAM emitter eliminates the external laser required by silicon- or silicon-on-insulator-based OAM emitters, thus demonstrating great potential for applications in communication systems and the quantum domain.

Surface Grating Fabrication by Inductively Coupled Plasma Dry Etching for InP-Based Photonic Integrated Circuits

“…During PIC fabrication, it is often required that we form fine structures with non‐uniform height. For examples, the fabrication of vortex beam emitters requires formation of shallow holes or surface gratings on top of the ridge waveguide of a ring resonator . Here, the deeply‐etched waveguide helps enhance the optical confinement of the core layer, thus reducing the bending loss in the ring resonator.…”

“…To form the ridge waveguide with surface gratings on top in a single‐step ICP dry etching process, the grating pattern is modified to a series of holes . Because of lag effect, the etch rate within the grating holes is lower than that in the open area.…”

Ultrafast control of fractional orbital angular momentum of microlaser emissions

“…For example, a reconfigurable FOAM transmitter has been recently demonstrated based on metagratings by varying illumination areas via a controllable aperture 25 . However, high-speed control and fast reconfigurability of FOAM, which is demanding in optical communication and computation applications, is challenging since the existing approaches are either static or mechanically slow despite several miniaturization efforts for on-chip OAM sources [26][27][28] . Ultrafast control based on nonresonant nonlinearities provides a viable route 29,30 ; however, this approach requires relatively high control powers and shows relatively low switching efficiency.…”

Direct Generation of Radially Polarized Vector Vortex Beam with an Exciton-Polariton Laser

“…Vector vortex beams can be generated by passing a free-space Gaussian laser beam or guided waves through additional polarization or phase modulation components [12][13][14][15][16], integrating polarization and phase control components with a fiber laser [17] or distributedfeedback semiconductor laser [18], or introducing external frequency-selective feedback and anisotropy to vertical-cavity surface-emitting lasers (VCSELs) [19]. These systems are often bulky, complex and difficult to control.…”