Laser to fiber optical coupling in photoplethysmography
An embodiment of a laser to fiber coupling apparatus having a substrate 110 that supports a laser mount 120 , to which is affixed a submount 130 and laser die 140 , and an open slot mount 150 , in which a light guide 160 is affixed with an adhesive 170 , such that the light from the laser 140 is coupled into the light guide 160 . The open slot arrangement permits the light guide to be moved in all six translational and rotational degrees of freedom to maximally couple the light from the laser to the light guide. Other embodiments are described and shown.
1. A photoplethysmographic device including an optics module, the optics module comprising:
a. a substrate having one or more pairs of mechanical mounts, each of the pairs of mechanical mounts comprised of a first mechanical mount and a second mechanical mount located in close proximity to the first mechanical mount;
b. a light source affixed to the first mechanical mount;
c. the second mechanical mount having an open slot formed therein designed to allow a light guide to be movably positioned in all translational and rotational axes within the open slot;
d. the light guide affixed within the open slot in a position to substantially maximally couple light emitted by the light source into the light guide.
2. The apparatus of claim 1 wherein at least one of the light sources for each of the pairs of mechanical mounts is a laser.
3. The apparatus of claim 1 wherein the light guide is fixed in position within the open slot by an adhesive.
4. The apparatus of claim 3 wherein the adhesive is a light-curable adhesive.
5. The apparatus of claim 1 wherein
the light guide is jacketed by a buffer,
the light guide protrudes from the buffer, and
both the light guide and the buffer are fixed in position within the open slot by an adhesive.
6. The apparatus of claim 5 wherein the adhesive is a light-curable adhesive.
7. The apparatus of claim 1 wherein the substrate is integral to one side of a thermoelectric cooler.
8. The apparatus of claim 1 wherein the substrate includes a substantially flat surface to allow the substrate to be mounted to one side of a thermoelectric cooler.
9. A photoplethysmographic device including an optics module, the optics module comprising:
a. a substrate including a first mechanical mount and a second mechanical mount;
b. a laser light source affixed to the first mechanical mount;
c. the second mechanical mount including an open slot designed to allow a light guide to be movably positioned in all translational and rotational axes within the open slot;
d. the light guide affixed with an adhesive within the open slot in a position that substantially maximally couples light emitted by the laser light source into the light guide.
10. A method for manufacturing an optics module in a photoplethysmographic measurement system comprising the steps of:
a. providing a substrate containing a plurality of one or more pairs of mechanical mounts;
b. providing a light source for each of the pairs of mechanical mounts;
c. providing a light guide for each of the pairs of mechanical mounts;
d. providing a first mechanical mount in each of the pairs of mechanical mounts;
e. affixing the first mechanical mount on the substrate;
f. affixing the light source to the first mechanical mount;
g. providing a second mechanical mount in each of the pairs of mechanical mounts;
h. affixing the second mechanical mount on the substrate in proximity to the first mechanical mount;
i. providing an open slot in the second mechanical mount;
j. aligning the light guide in the open slot to substantially maximally couple light, emitted by the light source held in the first mechanical mount, into the light guide;
k. affixing the light guide into position in the open slot.
11. The method of claim 10 wherein the step of affixing the light guide in position includes the step of applying an adhesive that makes contact with both the light guide and the slot.
12. The method of claim 11 wherein the step of applying the adhesive includes applying a light-curable adhesive.
13. The method of claim 10 wherein the step of providing the light guide includes the additional step of providing a light guide that is partially surrounded by a buffer and the step of affixing the light guide in position includes the additional steps of removing a portion of the buffer and of applying an adhesive to make contact with the light guide, the buffer, and the open slot.
14. The method of claim 13 wherein the step of applying the adhesive includes applying a light-curable adhesive.
15. The method of claim 14 wherein the step of affixing the light guide into position includes illuminating the light-curable adhesive to cause curing of the light-curable adhesive to a substantially rigid state.
16. The method of claim 10 wherein the step of providing a substrate includes providing a substrate that is integral to one side of a thermoelectric cooler.
17. The method of claim 10 wherein the step providing a substrate includes providing a substrate with a substantially flat surface to allow the substrate to be mounted to one side of a thermoelectric cooler.
18. The method of claim 10 wherein the step of providing a light source comprises the step of providing a laser light source.