Toward transformable photonics: Reversible deforming soft cavities, controlling their resonance split and directional emission

Abstract

We report on reversible and continuously deformable soft micro-resonators and the control of their resonance split and directional emission. Assisted by computerized holographic-tweezers, functioning as an optical deformer of our device, we gradually deform the shape and change the functionality of a droplet whispering-gallery cavity. For example, we continuously deform hexagonal cavities to rectangular ones and demonstrate switching to directionally emitting mode-of-operation, or splitting a resonant mode to a 10-GHz separated doublet. A continuous trend of improving spatial light modulators and tweezers suggests that our method is scalable and can control the shape and functionality of many individual devices. We also demonstrate optional solidification, proving the feasibility of transformer-enabled applications, including in printing optical circuits and multiwavelength optical networks.

Engineered entropic forces allow ultrastrong dynamical backaction

“…Early work by Ashkin and Dziedzic ( 52 ) used radiation pressure from a focussed laser beam to deform an air-liquid interface, using the direction of the deflection (outward) to answer open questions about the momentum of photons in a dielectric. The malleability of liquid-liquid and liquid-air interfaces has also been leveraged in optofluidic devices such as adaptive lenses and “lab-on-chip” applications ( 53 ), as well as for fluidic optomechanical resonators ( 54 – 56 ), the generation of giant optical nonlinearities ( 57 ), and transformable optical cavities ( 30 )—which have been proposed to reach the single-photon nonlinear regime ( 31 ). With the thick ( d = 24 nm) film considered here, the van der Waals pressure PvdW=normalρnormalαvdwd3, which opposes surface deformation and plays the role of the Young’s modulus in a solid, is two billion times softer than the underlying silica sphere ( 40 ).…”

“…We note however that the fountain pressure per absorbed photon is of similar magnitude to the thermoelastic stress which would occur in a crystalline material (see the Supplementary Materials). It is thus primarily the engineered ability to collect the thermal energy and operate with near optimally time-delayed forcing, combined with the much higher compliance of liquids compared to solids (29)(30)(31) which is responsible for the ultralow threshold observed here and not a fundamentally stronger nature of the fountain pressure force in superfluid helium. This makes these results broadly applicable to photothermally and electrothermally driven systems and different fluids.…”

Boundary Feedback Fiber Random Microcavity Laser Based on Disordered Cladding Structures

“…When the cavity size of lasers tends to be micrometers or even sub-micrometers, microcavity lasers have emerged, in which the compact internal environment will produce rich light-matter interactions [12][13][14]. By confining the complex disordered medium inside the microcavity, the output of the microcavity laser will exhibit a variety of complex characteristics as the disorder degree of the cavity boundary and the internal medium changes [15][16][17][18].…”