Waveguide grating structure and optical measurement arrangement

A sensor chip for interacting with at least one sample, the sensor chip comprising:

• a substrate;
• a one-dimensional or two-dimensional array of liquid holders or sample accommodating devices for accommodating at least one sample;
• and
• a waveguide grating structure on the substrate, the waveguide grating structure comprising at least one waveguide grating and having a one-dimensional or two-dimensional array of waveguide grating structure units or sensor locations,
• wherein at least one of the waveguide grating structure units or sensor locations comprises a signal sensing pad and a reference sensing pad,
• wherein the signal sensing pad or the reference sensing pad or both comprise at least two waveguide gratings with a waveguide structure region between the two waveguide gratings,
• wherein the signal sensing pad is covered at least partially by a chemofunctional signal layer,
• and wherein
• either the reference sensing pad is covered at least partially by a chemofunctional reference layer, and the sample contacts the chemofunctional signal layer and the chemofunctional reference layer in a same one of the liquid holders or sample accommodating devices,
• or a first sample contacts the chemofunctional signal layer in a first liquid holder or sample accommodating device, and a second sample, being the same or different from the first sample, or a liquid contacts at least partially the reference sensing pad in a second liquid holder or sample accommodating device,
• wherein a sensitivity of an effective refractive index N with respect to a perturbation effect ΔX is the same for the signal sensing pad and the reference sensing pad.

A sensor, comprising:

• at least one light source for producing at least one incident light field;
• a sensor chip for interacting with at least one sample, comprising:
• a substrate;
• a one-dimensional or two-dimensional array of liquid holders or sample accommodating devices for accommodating at least one sample;
• and
• a waveguide grating structure on the substrate, the waveguide grating structure comprising at least one waveguide grating and having a one-dimensional or two-dimensional array of waveguide grating structure units or sensor locations, wherein at least one of the waveguide grating structure units or sensor locations comprises a signal sensing pad and a reference sensing pad and wherein the signal sensing pad is covered at least partially by a chemofunctional signal layer, wherein a first sample contacts the chemofunctional signal layer in a first liquid holder or sample accommodating device, and a second sample, being the same or different from the first sample, or a liquid contacts at least partially the reference sensing pad in a second liquid holder or sample accommodating device, wherein a sensitivity of an effective refractive index N with respect to a perturbation effect ΔX is the same for the signal sensing pad and the reference sensing pad, and wherein the waveguide grating structure emits at least one light field when the incident light field at least partially illuminates the waveguide grating structure;
• and at least one detector device.