Dual coupler device, spectrometer including the dual coupler device, and non-invasive biometric sensor including the spectrometer

A spectrometer comprising:

• a first coupler layer configured to receive a light of a first polarization component among incident lights;
• a second coupler layer configured to receive a light of a second polarization component among the incident lights;
• and
• a photodetector configured to detect the light received by each of the first coupler layer and the second coupler layer,
• wherein a polarization direction of the light of the first polarization component is perpendicular to a polarization direction of the light of the second polarization component, and
• wherein the first coupler layer and the second coupler layer are spaced apart from each other and extended along a direction in which the incident lights propagate in the first coupler layer and the second coupler layer.

A non-invasive biometric sensor comprising:

• a light source configured to radiate an excitation light to an object;
• and
• a spectrometer configured to measure a spectrum distribution of a scattered light generated from the object by the excitation light,
• the spectrometer comprising:
• a first coupler layer configured to receive a light of a first polarization component among incident lights;
• a second coupler layer configured to receive a light of a second polarization component among the incident lights;
• and
• a photodetector configured to detect the light received by each of the first coupler layer and the second coupler layer,
• wherein a polarization direction of the light of the first polarization component is perpendicular to a polarization direction of the light of the second polarization component, and
• wherein the first coupler layer and the second coupler layer are spaced apart from each other and extended along a direction in which the incident lights propagate in the first coupler layer and the second coupler layer.

A spectrometer comprising:

• a first coupler layer configured to receive light of a p-polarization component through a first input coupler;
• a second coupler layer that is configured to receive light of an s-polarization component through a second input coupler and disposed to be apart from the first coupler layer in a first direction perpendicular to a second direction in which the light of the p-polarization component and the light of the s-polarization component propagate in the first coupler layer and the second coupler layer, respectively;
• and
• a reflector that is disposed to be apart from the first coupler layer and the second coupler layer in the first direction, aligned with the first input coupler and the second input coupler in the second direction, and configured to bounce off light incident from the first coupler input and the second input coupler back to the first input coupler and the second input coupler.