A system for on-chip analyte detection, comprising: a substrate; an analyte channel, disposed on the substrate, configured to receive a liquid containing analytes to be detected by the system; one or more first optical splitters disposed on the substrate; one or more second optical splitters disposed on the substrate; a first set of multiple single-mode waveguides, disposed on the substrate, that intersect the analyte channel, wherein the multiple single-mode waveguides comprised within the first set of multiple single-mode waveguides are configured to receive, via one or more first optical splitters, input light of a first wavelength that has arrived at a first input port of the first set of multiple single-mode waveguides and wherein the first set of multiple single-mode waveguides is configured to direct a first multi-spot pattern generated from the input light of the first wavelength onto the intersecting analyte channel; a second set of multiple single-mode waveguides, disposed on the substrate, that intersect the analyte channel, wherein the multiple single-mode waveguides comprised within the second set of multiple single-mode waveguides are configured to receive, via one or more second optical splitters, input light of a second wavelength that has arrived at a second input port of the second set of multiple single-mode waveguides and wherein the second set of multiple single-mode waveguides is configured to direct a second multi-spot pattern generated from the input light of the second wavelength onto the intersecting analyte channel; and a demultiplexing multi-mode interference waveguide, disposed on the substrate, the demultiplexing MMI waveguide comprising: a third input port, disposed at a first end of the demultiplexing MMI waveguide, configured to receive input light of the first wavelength and input light of the second wavelength; a first output port, disposed at a second end of the demultiplexing MMI waveguide opposite the first end, wherein light of the first wavelength is directed to the first input port of the first set of multiple single-mode waveguides and a second output port, disposed at the second end of the demultiplexing MMI waveguide, configured to output a mirror-image of light of the second wavelength, wherein light of the second wavelength is directed to the second input port of the second set of multiple single-mode waveguides, the system being characterized in that each of the one or more first and second optical splitters (718a, 718b) is a Y-splitter. a substrate; an analyte channel, disposed on the substrate, configured to receive a liquid containing analytes to be detected by the system; one or more first optical splitters disposed on the substrate; one or more second optical splitters disposed on the substrate; a first set of multiple single-mode waveguides, disposed on the substrate, that intersect the analyte channel, wherein the multiple single-mode waveguides comprised within the first set of multiple single-mode waveguides are configured to receive, via one or more first optical splitters, input light of a first wavelength that has arrived at a first input port of the first set of multiple single-mode waveguides and wherein the first set of multiple single-mode waveguides is configured to direct a first multi-spot pattern generated from the input light of the first wavelength onto the intersecting analyte channel; a second set of multiple single-mode waveguides, disposed on the substrate, that intersect the analyte channel, wherein the multiple single-mode waveguides comprised within the second set of multiple single-mode waveguides are configured to receive, via one or more second optical splitters, input light of a second wavelength that has arrived at a second input port of the second set of multiple single-mode waveguides and wherein the second set of multiple single-mode waveguides is configured to direct a second multi-spot pattern generated from the input light of the second wavelength onto the intersecting analyte channel; and a demultiplexing multi-mode interference waveguide, disposed on the substrate, the demultiplexing MMI waveguide comprising: a third input port, disposed at a first end of the demultiplexing MMI waveguide, configured to receive input light of the first wavelength and input light of the second wavelength; a first output port, disposed at a second end of the demultiplexing MMI waveguide opposite the first end, wherein light of the first wavelength is directed to the first input port of the first set of multiple single-mode waveguides and a second output port, disposed at the second end of the demultiplexing MMI waveguide, configured to output a mirror-image of light of the second wavelength, wherein light of the second wavelength is directed to the second input port of the second set of multiple single-mode waveguides, the system being characterized in that each of the one or more first and second optical splitters (718a, 718b) is a Y-splitter. a third input port, disposed at a first end of the demultiplexing MMI waveguide, configured to receive input light of the first wavelength and input light of the second wavelength; a first output port, disposed at a second end of the demultiplexing MMI waveguide opposite the first end, wherein light of the first wavelength is directed to the first input port of the first set of multiple single-mode waveguides and a second output port, disposed at the second end of the demultiplexing MMI waveguide, configured to output a mirror-image of light of the second wavelength, wherein light of the second wavelength is directed to the second input port of the second set of multiple single-mode waveguides,