Optical sensor chip and optical sensing system

An optical sensor chip characterized in that the chip comprises a bottom cladding, a top cladding stacked on the bottom cladding and an optical waveguide core,

• wherein the optical waveguide core is arranged between the top cladding and the bottom cladding, the top cladding is provided with an opened region for accommodating a sample to be tested, and a part of the optical waveguide core is exposed through the opened region;
• the optical waveguide core comprises a first polarization rotator and a first polarization splitter;
• the first polarization splitter comprises one input port and two output ports;
• the two output ports comprise a through port and a coupling port;
• the through port and the coupling port are both used for outputting polarized light;
• and
• the first polarization rotator is collinear with the first polarization splitter, the first polarization rotator is provided with a first end and a second end, the second end of the first polarization rotator is communicated with the input port of the first polarization splitter, and a dimension of the first polarization rotator gradually increases along a direction from the first end to the second end;
• a light input from the first end is in a basic TM mode, after passing through the first polarization rotator with opened region, light will be completely or partially converted to a TE mode, which is output at the coupling port as a basic TE mode, while remaining incompletely converted TM is still output at the through port in the basic TM mode;
• after passing through the first polarization splitter, the TM polarized light and TE polarized light from the light output by the first polarization rotator is separated and output at the through port and the coupling port, respectively;
• and material information or biological/chemical target concentration of the sample to be tested can be traced according to the TM polarized light being output and the TE polarized light being output.