INTEGRATED LIGHT SOURCE ASSEMBLY WITH LASER COUPLING FOR A WEARABLE OPTICAL MEASUREMENT SYSTEM
A wearable module for use in an optical measurement system may include a first light source configured to emit a first light pulse in a first wavelength, a second light source configured to emit a second light pulse in a second wavelength that is different from the first wavelength, a light guide configured to guide the first light pulse and the second light pulse toward a target within a body of a user; an optical member configured to receive the first light pulse from the first light source and the second light pulse from the second light source and direct the first light pulse and the second light pulse to the light guide, and a housing that houses the first light source, the second light source, and the optical member.
1 . A wearable module for use in an optical measurement system, the wearable module comprising:
a first light source configured to emit a first light pulse in a first wavelength;
a second light source configured to emit a second light pulse in a second wavelength that is different from the first wavelength;
a light guide configured to guide the first light pulse and the second light pulse toward a target within a body of a user;
an optical member configured to receive the first light pulse from the first light source and the second light pulse from the second light source and direct the first light pulse and the second light pulse to the light guide; and
a housing that houses the first light source, the second light source, and the optical member.
2 . The wearable module of claim 1 , wherein the housing further houses at least a portion of the light guide.
3 . The wearable module of claim 1 , wherein the first light source and the second light source each comprises a laser diode.
4 . The wearable module of claim 1 , wherein the optical member comprises a prism, a mirror, or another light guide.
5 . The wearable module of claim 1 , wherein:
the optical member is configured to direct the first light pulse and the second light pulse to a proximal end of the light guide, and
the light guide is configured to emit the first light pulse and the second light pulse from a distal end of the light guide.
6 . The wearable module of claim 5 , further comprising a light guide block comprising a chamber,
wherein:
the light guide is disposed in the chamber, and
the chamber maintains the proximal end of the light guide in optical alignment with the optical member.
7 . The wearable module of claim 1 , further comprising a support assembly,
wherein:
the first light source, the second light source, and the optical member are disposed on the support assembly, and
the support assembly maintains the optical member in optical alignment with a proximal end of the light guide.
8 . The wearable module of claim 1 , wherein a distal end portion of the light guide protrudes from a top surface of the housing.
9 . The wearable module of claim 1 , wherein the light guide comprises a plurality of optical fibers.
10 . The wearable module of claim 1 , wherein the wearable module is included in a head-mountable component configured to be worn on a head of a user.
11 . The wearable module of claim 1 , further comprising a controller configured to control the first light source and the second light source to output one or more of the first light pulse or the second light pulse.
12 . The wearable module of claim 1 , wherein the target comprises a brain of the user.
13 . The wearable module of claim 1 , further comprising:
at least one time-resolved single-photon photodetector configured to detect photons from at least one of the first light pulse and the second light pulse after the photons are scattered by the target, and
at least one light-receiving light guide configured to receive the photons after the photons are scattered by the target and guide the photons to the at least one photodetector,
wherein the housing houses the at least one photodetector and at least a portion of the at least one light-receiving light guide.
14 . The wearable module of claim 13 , further comprising at least one time-to-digital converter (TDC),
wherein the at least one TDC is configured to measure a time difference between an occurrence of the first light pulse or the second light pulse and an occurrence of an output pulse generated by the at least one photodetector and indicating that the at least one photodetector has detected a photon.
15 . The wearable module of claim 13 , further comprising a signal processing circuit configured to:
determine a temporal distribution of the photons detected by the at least one photodetector, and
generate a histogram based on the temporal distribution of the photons.
16 . The wearable module of claim 13 , wherein the at least one photodetector comprises a plurality of single-photon avalanche diode (SPAD) circuits.
17 . The wearable module of claim 13 , wherein a distal end portion of the at least one light-receiving light guide protrudes from a top surface of the housing.
18 . The wearable module of claim 17 , further comprising a spring member configured to bias the distal end portion of the at least one light-receiving light guide away from the top surface of the housing.
19 . The wearable module of claim 17 , wherein the at least one light-receiving light guide is movable along an optical axis of the at least one light-receiving light guide.
20 . The wearable module of claim 17 , wherein the at least one light-receiving light guide is configured to be pressed toward the top surface of the housing by the body of the user when the wearable module is worn by the user.
21 - 30 . (canceled)