US 11,656,485 B2
Photonic bandgap phase modulator, optical filter bank, photonic computing system, and methods of use
Mitchell A. Nahmias, Menlo Park, CA (US); and Michael Gao, Menlo Park, CA (US)
Assigned to Luminous Computing, Inc., Santa Clara, CA (US)
Filed by Luminous Computing, Inc., Menlo Park, CA (US)
Filed on Jul. 6, 2020, as Appl. No. 16/921,475.
Claims priority of provisional application 62/873,006, filed on Jul. 11, 2019.
Prior Publication US 2021/0011312 A1, Jan. 14, 2021
Int. Cl. G02F 1/025 (2006.01); G02F 1/03 (2006.01); G02F 1/035 (2006.01)
CPC G02F 1/0327 (2013.01) [G02F 1/025 (2013.01); G02F 1/035 (2013.01); G02F 2202/32 (2013.01); G02F 2203/50 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A system for optical modulation, the system comprising:
a first waveguide defining an optical input;
a second waveguide;
an output coupler that optically couples the first waveguide to the second waveguide, the output coupler defining an optical output;
a first photonic bandgap phase modulator comprising a plurality of modulator segments, the first photonic bandgap phase modulator arranged along the first waveguide; and
a second photonic bandgap phase modulator comprising a second plurality of modulator segments, the second photonic bandgap phase modulator arranged along the second waveguide;
wherein:
the system defines a light propagation path from the optical input to the optical output, wherein the first and second photonic bandgap phase modulators precede the output coupler along the light propagation path;
each modulator segment of the plurality and each modulator segment of the second plurality comprises a semiconductor region comprising an n-type portion and a p-type portion, wherein:
the semiconductor region defines a photonic crystal region, wherein the light propagation path intersects the photonic crystal region, thereby defining a segment length through the photonic crystal region; and
the semiconductor region defines a semiconductor junction between the n-type portion and the p-type portion;
each modulator segment of the plurality and each modulator segment of the second plurality accepts a respective electrical input between the n-type portion and the p-type portion of the modulator segment; and
for each modulator segment of the plurality:
the respective electrical input is operable to transition the modulator segment between:
a first mode, in which light of a reference wavelength propagates through the photonic crystal region of the modulator segment in a first photonic band defining a first refractive index; and
a second mode, in which light of the reference wavelength propagates through the photonic crystal region of the modulator segment in a second photonic band defining a second refractive index substantially different from the first refractive index;
light of a second wavelength propagates through the photonic crystal region of the modulator segment in the first photonic band in both the first mode and the second mode; and
light of a third wavelength propagates through the photonic crystal region of the modulator segment in the second photonic band in both the first mode and the second mode;
for each modulator segment of the second plurality:
the respective electrical input is operable to transition the modulator segment between:
a first mode, in which light of the second wavelength propagates through the photonic crystal region of the modulator segment in a third photonic band defining a third refractive index; and
a second mode, in which light of the second wavelength propagates through the photonic crystal region of the modulator segment in a fourth photonic band defining a fourth refractive index substantially different from the third refractive index; and
light of the reference wavelength and the third wavelength propagates through the photonic crystal region of the modulator segment in the fourth photonic band in both the first mode and the second mode.