US 12,468,090 B2
Ultrasound sensing and imaging based on whispering-gallery-mode (WGM) microresonators
Lan Yang, St. Louis, MO (US); Guangming Zhao, St. Louis, MO (US); Xuefeng Jiang, St. Louis, MO (US); and Yihang Li, St. Louis, MO (US)
Assigned to Washington University, St. Louis, MO (US)
Appl. No. 17/761,026
Filed by Washington University, St. Louis, MO (US)
PCT Filed Sep. 18, 2020, PCT No. PCT/US2020/051596
§ 371(c)(1), (2) Date Mar. 16, 2022,
PCT Pub. No. WO2021/055823, PCT Pub. Date Mar. 25, 2021.
Claims priority of provisional application 62/901,883, filed on Sep. 18, 2019.
Prior Publication US 2022/0350082 A1, Nov. 3, 2022
Int. Cl. G02B 6/293 (2006.01); A61B 5/00 (2006.01); A61B 8/00 (2006.01); G01N 29/06 (2006.01)
CPC G02B 6/29341 (2013.01) [A61B 5/0095 (2013.01); A61B 8/4444 (2013.01); A61B 8/565 (2013.01); G01N 29/0654 (2013.01); A61B 2562/0238 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A sensor, comprising:
an optical whispering gallery mode resonator for sensing acoustic signals;
a coupling waveguide for optically coupling to the resonator, the coupling waveguide being spaced from the resonator by a separation gap; and
a polymer encasing a portion of the coupling waveguide and the resonator and filling the separation gap, the polymer having a dimension engineered to enhance acoustic focus on the optical whispering gallery mode resonator, wherein the dimension engineered to enhance acoustic focus on the optical whispering gallery mode resonator comprises an upper boundary of the polymer being a convex upper boundary;
wherein the resonator and the coupling waveguide each have higher refractive indices than a refractive index of the polymer, and the separation gap is sized such that the sensor r is configured to operate at critical coupling of the resonator and the coupling waveguide or at a maximum loading factor with the polymer filling the separation gap.