Tunable hybrid III-V/IV laser sensor system-on-a chip for real-time monitoring of a blood constituent concentration level
A spectroscopic laser sensor based on hybrid lll-V/IV system-on-a-chip technology. The laser sensor is configured to either (i) be used with a fiber-optic probe connected to an intravenous/intra-arterial optical catheter for direct invasive blood analyte concentration level measurement or (ii) be used to measure blood analyte concentration level non-invasively through an optical interface attached, e.g., to the skin or fingernail bed of a human. The sensor includes a lll-V gain-chip, e.g., an AIGalnAsSb/GaSb based gain-chip, and a photonic integrated circuit, with laser wavelength filtering, laser wavelength tuning, laser wavelength monitoring, laser signal monitoring and signal output sections realized on a chip by combining IV-based semiconductor substrates and flip-chip AIGalnAsSb/GaSb based photodetectors and embedded electronics for signal processing. Embodiments of the invention may be applied for real-time monitoring of critical blood analyte concentration levels such as lactates, urea, glucose, ammonia, albumin, etc.
1 . An optical sensing module suitable for wearable devices, the optical sensing module comprising:
(a) a silicon or silicon nitride transmitter photonic integrated circuit (PIC), the transmitter PIC comprising:
(i) a plurality of lasers, each laser of the plurality of lasers operating at a wavelength that is different from wavelengths of other lasers of the plurality of lasers;
(b) an optical manipulation region, the optical manipulation region comprising at least a ring resonator, a filter, a mirror, and an optical multiplexer; and
(c) one or more optical outputs for light originating from the plurality of lasers.
2 . The optical sensing module of claim 1 , further comprising at least one additional optical manipulation element comprising one or more of:
power taps, lens(es), power splitter(s), filter(s), mirror(s) and polarization rotator(s).
3 . The optical sensing module of claim 1 , wherein the plurality of lasers includes one or more lasers having a III-V RSOA gain, laser chips or coupon that is hybrid integrated to the PIC such that an optical mode in the III-V RSOA gain or laser waveguide is edge-coupled to one or more waveguides of the PIC.
4 . The optical sensing module of claim 1 , wherein the mirror of the optical manipulation region is configured to couple light from all of the plurality of lasers out of the optical sensing module at a single optical output.
5 . The optical sensing module of claim 1 , further comprising one or more photodetectors.
6 . The optical sensing module of claim 5 , wherein at least one of the one or more photodetectors is located on the transmitter PIC such that the PIC is a transmitter/receiver PIC.
7 . The optical sensing module of claim 5 , wherein the one or more photodetectors are located separately from the transmitter PIC.
8 . The optical sensing module of claim 1 , further comprising one or more of: laser drivers, modulator drivers, phase controllers, power supply electronics, and micro-controller units.
9 . The optical sensing module of claim 1 , wherein the plurality of lasers is placed onto the PIC via flip-chip die bonding or micro transfer printing.
10 . The optical sensing module of claim 1 , wherein the optical sensing module comprises a photodetector configured to make a recording and a tunable laser configured to sweep over a range of wavelengths.
11 . An optical sensor for use in wearable devices, the optical sensor comprising:
a III-V semiconductor-based gain-chip,
at least one group III-V photodiode,
a group-IV semiconductor based photonic integrated circuit comprising an array of lasers, wherein each laser of the array of lasers is targeted at a different spectral region,
a plurality of optical elements, each optical element coupled to at least one laser of the array of lasers, the plurality of optical elements comprising one or more optical manipulation devices comprising at least a Vernier-filter, a ring resonator, a mirror, and a multiplexer; and
at least one interface coupled to each laser of the array of lasers and the at least one interface configured to transmit light from each laser of the array of lasers to a target.
12 . The optical sensor of claim 11 , wherein the one or more optical manipulation devices further comprises a mode spot size converter.
13 . The optical sensor of claim 11 , wherein the one or more optical manipulation devices further comprises a coupled resonator cavity.
14 . The optical sensor of claim 11 , wherein the one or more optical manipulation devices further comprises a wide band reflector multimode interference device.
15 . The optical sensor of claim 11 , wherein the multiplexer comprises a Mach-Zehnder interferometer.
16 . The optical sensor of claim 11 , wherein the one or more optical manipulation devices further comprises a distributed Bragg reflector.
17 . The optical sensor of claim 11 , wherein the one or more optical manipulation devices further comprises a lens.
18 . The optical sensor of claim 11 , wherein the one or more optical manipulation devices further comprises at least one of a mode spot size converter, a coupled resonator cavity, a wide band reflector multimode interference device, a Mach-Zehnder interferometer, a distributed Bragg reflector, and a lens.
19 . The optical sensor of claim 11 , wherein additional optical manipulation including at least one of wavelength filtering, power filtering, and tuning is performed on the group-IV semiconductor based photonic integrated circuit.
20 . The optical sensor of claim 11 , wherein the III-V semiconductor-based gain-chip is edge coupled to the group-IV semiconductor based photonic integrated circuit.
21 . The optical sensor of claim 11 , wherein at least one photodiode is disposed remotely from the group-IV semiconductor based photonic integrated circuit, and is located on a carrier other than the group-IV semiconductor based photonic integrated circuit.
22 . The optical sensor of claim 11 , wherein the one or more optical manipulation devices further comprises one or more power taps, lens(es), power splitter(s), and polarization rotator(s).
23 . An optical sensor for use in wearable devices, the optical sensor comprising:
a III-V semiconductor-based gain-chip,
at least one group III-V photodiode,
a group-IV semiconductor based photonic integrated circuit comprising an array of lasers, wherein each laser of the array of lasers is targeted at a different spectral region,
a plurality of optical elements, each optical element coupled to at least one laser of the array of lasers, the plurality of optical elements comprising one or more optical manipulation devices;
at least one interface coupled to each laser of the array of lasers and the at least one interface configured to transmit light from each laser of the array of lasers to a target; and
a processor;
wherein the optical sensor is configured to:
receive reflected light from the target via the at least one interface;
apply a pre-trained algorithm to the received reflected light to convert the reflected light from the target into an electrical signal;
convert, using the electrical signal, the reflected light from the target into an absorbed light at the target, the absorbed light at the target comprising a complex absorption spectrum;
determine a water concentration level of the target using the complex absorption spectrum;
remove a baseline from the complex absorption spectrum, the baseline calculated based on the determined water concentration level;
decompose the complex absorption spectrum; and
based on the decomposition of the complex absorption spectrum, determine a concentration level of at least one analyte at the target.
24 . The optical sensor of claim 23 , wherein receiving reflected light from the target via the at least one interface comprises receiving reflected light from the target via a plurality of interfaces.
25 . The optical sensor of claim 24 , wherein the complex absorption spectrum includes a plurality of individual absorbance spectral components received via the plurality of interfaces.
26 . The optical sensor of claim 23 , wherein the one or more optical manipulation devices comprise one or more of a ring resonator, a filter, a mirror, and a multiplexer.
27 . The optical sensor of claim 23 , further comprising one or more photodetectors.
28 . The optical sensor of claim 27 , wherein the one or more photodetectors are configured to make a recording.
29 . The optical sensor of claim 23 , further comprising one or more of: laser drivers, modulator drivers, phase controllers, power supply electronics, and micro-controller units.