Selected and Enhanced Single Whispering-Gallery Mode Emission from a Mesostructured Nanomembrane Microcavity

Abstract

Quantum sciences are revolutionizing computing and communication technologies, in which single-photon emitters are the key components for creating strong quantum entanglement. Color centers in diamonds in coupled-cavity systems are considered great candidates for the efficient generation of quantum carriers over other solid-state emitters. Owing to the multi-mode nature of high quality factor (Q) diamond cavities, however, it is a grand challenge to the achievement of single photon emission with high rate and indistinguishability. To this end, a single-mode high-Q diamond cavity is highly desired. Here, we report a diamond mesostructured nanomembrane microcavity of a discrete rotational symmetry that selectively produces the desired single-mode emission in a broad spectrum. The strategic rolling up of a flexible diamond nanomembrane with aligned holes effectively defines the designed symmetry while maintaining the high-Q resonance through the whispering-gallery mode supported in the central hollow microcavity. The demonstrated diamond mesostructured microcavity features a distinct and enhanced single-mode emission, a step toward efficient quantum sources with designed positions or bands for quantum information technology.

Recent Progress on Optoplasmonic Whispering‐Gallery‐Mode Microcavities

“…[ 49,50 ] In particular, vertical microring cavities, fabricated by rolled‐up nanotech, [ 51–53 ] possess ultra‐thin cavity walls down to 150 nm, enabling strong evanescent field coupling to on‐chip waveguides, highly sensitive label‐free optical sensing performance, and enhanced light‐matter interactions. [ 26,54–64 ]…”

Single Whispering Gallery Mode in Mesh‐Structured Tubular Microcavity with Tunable Axial Confinement

“…[ 52 ] In addition, the subwavelength wall thickness also plays an important role in confining light propagation along radial direction, and thus only the fundamental radial mode is demonstrated. [ 46 ] Moreover, affected by the wavelength‐scale axial barrier length, WGM is further restricted with the lowest axial mode index of 1.…”

“…[38] In the case of tubular microcavities with the special geometrical feature, [43] additional degrees of freedom can be employed along the axial direction, [44,45] and therefore, strategies based on axial confinement along microtubes have been reported. Tian et al [46] utilized origami-inspired technology to fabricate a diamond mesostructured microcavity with a discrete rotational symmetry, realizing a single WGM zero-phonon line emission with a high signal-to-noise ratio. However, with complex structure and delicate fabrication process, precise manipulation of the single-mode WGM microcavity has not been systematically demonstrated yet.…”

Emerging opportunities for ultra-high Q whispering gallery mode microcavities

“…Microdisks and microrings (Figure 1(c ; thus, a battery-operated integrated frequency comb has been experimentally demonstrated [11]. Recently, several interesting approaches, including the use of roll-up microtubular cavity, for fabricating WGM resonators have been demonstrated (Figure 1(d)) [12]. This cavity makes WGMs compatible with microfluidics and is suitable for integration with many liquid materials.…”

“…Color online) Configurations of WGM optical microcavities. (a) Microsphere[7], (b) microtoroids[8], (c) microring[10], (d) microtube[12], (e) bottom-up polygon cavity, and (f) microdisk[13].…”