US 12,444,462 B2
Electro-optical high bandwidth ultrafast differential RAM
Ajey Poovannummoottil Jacob, Los Angeles, CA (US); Akhilesh Ramlaut Jaiswal, Los Angeles, CA (US); Ramesh Kudalippalliyalil, Los Angeles, CA (US); and Sujith Chandran, Los Angeles, CA (US)
Assigned to University of Southern California, Los Angeles, CA (US)
Appl. No. 18/281,662
Filed by UNIVERSITY OF SOUTHERN CALIFORNIA, Los Angeles, CA (US)
PCT Filed Mar. 14, 2022, PCT No. PCT/US2022/020210
§ 371(c)(1), (2) Date Sep. 12, 2023,
PCT Pub. No. WO2022/192784, PCT Pub. Date Sep. 15, 2022.
Claims priority of provisional application 63/160,173, filed on Mar. 12, 2021.
Prior Publication US 2024/0170055 A1, May 23, 2024
Int. Cl. G11C 13/04 (2006.01); G02F 1/225 (2006.01); G11C 11/42 (2006.01)
CPC G11C 11/42 (2013.01) [G02F 1/225 (2013.01); G11C 13/047 (2013.01); G02F 2203/15 (2013.01)] 47 Claims
OG exemplary drawing
 
1. A LEO-RAM cell comprising:
a first ring resonator R1 that couples a first waveguide W1 to a second waveguide W2 such that the first waveguide W1 receives a first optical signal S1,
a second ring resonator R2 that couples a third waveguide W3 to a fourth waveguide W4 such that the third waveguide W3 receives a second optical signal S2;
a first phototransistor T1 having a base (or gate) coupled to an output of the second ring resonator R2 through the third waveguide W3 and is configured to operate the first ring resonator R1 wherein the first ring resonator R1 is configured to operate at a first resonant wavelength λbit when the first phototransistor T1 is OFF such that light output appears at a drop port of the first ring resonator R1 thereby switching second phototransistor T2 “ON” and configured to operate at non-resonant for λbit when the first phototransistor T1 is “ON” such that second phototransistor T2 turns “OFF”; and
a second phototransistor T2 having a base (or gate) coupled to an output of the first ring resonator R1 through the second waveguide W2 and is configured to operate the second ring resonator R2; wherein the second ring resonator R2 is configured to operate at same resonant wavelength λbit when the second phototransistor T2 is “ON” such that when second ring resonator R2 is at resonance, no light will transfer to first phototransistor T1.