High-Speed Directly Modulated Cylindrical Vector Beam Lasers

Abstract

Cylindrical vector (CV) beams are highly desirable for wide applications ranging from manipulation to communications. Despite diverse schemes of CV beam emitters, the efficient generation of vector beams by active photonic integrated devices, especially for direct modulation, is still an outstanding challenge. Here, we report the first high-speed directly modulated CV beam laser under electrical pumping. InP-based microring cavities with two sets of optimized second-order gratings enable single-mode lasing and efficient emission assisted by ion implantation. The high-differential-gain multiplequantum-well structure and small active region benefit high-speed modulation. The surface emission facilitates easy 2D array integration. CV beam lasing is achieved with >1 mW output power and ∼50 dB side-mode suppression ratio (SMSR). CV beam lasers at 8−20 Gbit/s are realized in the experiment. Moreover, a 2 km fiber vector eigenmode transmission link, seeded by a 10 Gbit/s directly modulated CV beam laser, is also demonstrated with favorable performance. These may open a door to find more CV beam enabled classical and quantum communication applications employing integrated lasers.

Generation and Detection of Structured Light: A Review

“…Integrated devices with small volumes for generating various structured light beams are, remarkably, showing a promise prospect. Here, we present different types of integrated devices for generating structured light beams based on diverse materials, including silicon [55][56][57][58][59][60], silica [61][62][63], metals [64][65][66], crystal [67], InP [68][69][70][71], and so on. Among them, the active material InP can be used to build a structured light beam laser.…”

“…A beam out from the VCSEL is converted to a higher-order optical vortex beam by such a spiral phase plate. Shown in Figure 5E is a high-speed directly modulated cylindrical vector beam laser, enabling single cylindrical vector beam lasing and efficient emission, assisted by ion implantation, which is manufactured by placing two sets of optimized second-order gratings in InP-based microring cavities [70,71]. Eight to 20 Gbit/s cylindrical vector beam lasing is achieved with >1 mW output power and a ∼50 dBside-mode suppression ratio.…”

“…Additionally, we may also classify these integrated devices based on different working principles, such as metasurface [63][64][65][66], bounded in the continuum [72,73], and WGM waveguides [55,69,70].…”

Vector Beam Generation from Standing Hollow GaN Nanowire Lasers on Sapphire Substrates

“…Recently, signal processing of vector beams using a ring resonator laser has been demonstrated. 22 This method generates radially polarized light and is capable of fast signal modulation. Vector beam generation is also possible from photonic crystal lasers.…”

Vertical Emitting Nanowire Vector Beam Lasers

“…One inspiring approach to generating VB lasers is based on constructing the semiconductor optical cavity for mode selection to realize compact active laser sources. The microdisk or microring cavity is a candidate structure, in which whispering gallery modes can be supported and circulated. − However, additional complex refractive-index modulation is essential for unidirectional light propagation to achieve VBs, which requires complicated and precise fabrication processes of the cavity. To support the large volume of the whispering gallery mode, the dimensions of these cavities cannot be reduced to the wavelength scale, which is hard to meet the demand for continuous miniaturization of photonic integrated chips .…”