Systems and methods for characterizing near field transducer performance at wafer level using asymmetric interference waveguides
View Patent ↗Systems and methods and apparatuses for characterizing near field transducer performance at wafer level using asymmetric interference waveguides are provided. One such system includes a light source, an input grating configured to receive light from the light source, a first waveguide arm and a second waveguide arm, each configured to receive the light, a surface plasmon receptor optically coupled to the first waveguide arm and the second waveguide arm and configured to receive light from the first waveguide arm in a first direction and the second waveguide arm in a second direction opposite of the first direction, where the first and the second waveguide arms are configured to induce a preselected phase difference in light arriving at the surface plasmon receptor, and an output grating optically coupled to the surface plasmon receptor, and a light detector coupled to, and configured to detect light from, the first output grating.
1. A system for characterizing performance of a surface plasmon receptor at wafer level, the system comprising:
a light source;
an input grating configured to receive light from the light source;
a splitter configured to receive the light from the input grating;
a first waveguide arm;
a second waveguide arm, wherein the splitter is configured to split the light into the first waveguide arm and the second waveguide arm;
a surface plasmon receptor optically coupled to the first waveguide arm and the second waveguide arm and configured to receive light from the first waveguide arm in a first direction and the second waveguide arm in a second direction opposite of the first direction, wherein the first and the second waveguide arms are configured to induce a preselected phase difference in light arriving at the surface plasmon receptor;
a third waveguide arm optically coupled to the surface plasmon receptor;
a first output grating coupled to the third waveguide arm; and
a light detector coupled to, and configured to detect light from, the first output grating.
2. The system of claim 1 , wherein the first waveguide arm and the second waveguide arm are configured to facilitate a wavelength tuning of light arriving at the surface plasmon receptor.
3. The system of claim 1 , wherein a length of the first waveguide arm is unequal to a length of the second waveguide arm.
4. The system of claim 1 , further comprising:
a fourth waveguide arm optically coupled to the surface plasmon receptor; and
a second output grating coupled to the fourth waveguide arm,
wherein the light detector is coupled to, and configured to detect light from, the second output grating.
5. The system of claim 4 , further comprising:
a second splitter disposed along the first waveguide and configured to receive light from the surface plasmon receptor, wherein the third waveguide arm extends from the second splitter to the first output grating; and
a third splitter disposed along the second waveguide and configured to receive light from the surface plasmon receptor, wherein the fourth waveguide arm extends from the third splitter to the second output grating.
6. The system of claim 1 , further comprising a controller coupled to the light source and the light detector, wherein the controller is configured to scan through a range of wavelengths of light generated by the light source.
7. The system of claim 6 , wherein the controller is configured to determine a resonance signature of the surface plasmon receptor.
8. The system of claim 6 , wherein the controller is configured to determine a wavelength of light for a peak output at the light detector.
9. The system of claim 8 , wherein a position of the surface plasmon receptor between the first waveguide arm and the second waveguide arm is adjusted based on the peak output.
10. The system of claim 1 , wherein the first and the second waveguide arms are configured such that light arriving at the surface plasmon receptor from the first waveguide arm interferes with light arriving at the surface plasmon receptor from the second waveguide arm.
11. The system of claim 1 , wherein the light detected by the light detector is for generating a measured performance of the surface plasmon receptor, and the measured performance is for adjusting a fabrication of the surface plasmon receptor.
12. The system of claim 11 , wherein the measured performance is for adjusting a preselected characteristic of the surface plasmon receptor during the fabrication, wherein the preselected characteristic is selected from the group consisting of a size, a material, a shape, and combinations thereof.
13. The system of claim 1 , wherein the surface plasmon receptor comprises a near field transducer (NFT).
14. The system of claim 13 , wherein the NFT comprises a disk shape.
15. A method for characterizing performance of a surface plasmon receptor at wafer level, the method comprising:
providing a light source;
providing an input grating configured to receive light from the light source;
providing a splitter configured to receive the light from the input grating;
providing a first waveguide arm;
providing a second waveguide arm, wherein the splitter is configured to split the light into the first waveguide arm and the second waveguide arm;
providing a surface plasmon receptor optically coupled to the first waveguide arm and the second waveguide arm and configured to receive light from the first waveguide arm in a first direction and the second waveguide arm in a second direction opposite of the first direction, wherein the first and the second waveguide arms are configured to induce a preselected phase difference in light arriving at the surface plasmon receptor;
providing a third waveguide arm optically coupled to the surface plasmon receptor;
providing a first output grating coupled to the third waveguide arm;
providing a light detector coupled to, and configured to detect light from, the first output grating;
generating light at the light source at a range of wavelengths;
applying the light generated at the light source to the input grating; and
determining a wavelength at which an output of the light detector is maximum for the range.
16. The method of claim 15 , further comprising adjusting a process for manufacturing devices comprising the surface plasmon receptor based on a measured performance of the surface plasmon receptor including the wavelength at which the output of the light detector is maximum.
17. The method of claim 16 , wherein the adjusting the process for manufacturing devices comprising the surface plasmon receptor comprises adjusting a preselected characteristic of the surface plasmon receptor based on the measured performance of the surface plasmon receptor, wherein the preselected characteristic is selected from the group consisting of a size, a material, a shape, and combinations thereof.
18. The method of claim 17 , wherein the first waveguide arm and the second waveguide arm are configured to facilitate a wavelength tuning of light arriving at the surface plasmon receptor.
19. The method of claim 15 , wherein a length of the first waveguide arm is unequal to a length of the second waveguide arm.
20. The method of claim 15 , further comprising:
a fourth waveguide arm optically coupled to the surface plasmon receptor; and
a second output grating coupled to the fourth waveguide arm,
wherein the light detector is coupled to, and configured to detect light from, the second output grating.
21. The method of claim 20 , further comprising:
a second splitter disposed along the first waveguide and configured to receive light from the surface plasmon receptor, wherein the third waveguide arm extends from the second splitter to the first output grating; and
a third splitter disposed along the second waveguide and configured to receive light from the surface plasmon receptor, wherein the fourth waveguide arm extends from the third splitter to the second output grating.
22. The method of claim 15 , further comprising determining a resonance signature of the surface plasmon receptor.
23. The method of claim 15 , wherein a position of the surface plasmon receptor between the first waveguide arm and the second waveguide arm is adjusted based on the wavelength at which the output of the light detector is maximum for the range.
24. The method of claim 15 , wherein the first and the second waveguide arms are configured such that light arriving at the surface plasmon receptor from the first waveguide arm interferes with light arriving at the surface plasmon receptor from the second waveguide arm.
25. The method of claim 15 , wherein the surface plasmon receptor comprises a near field transducer (NFT).
26. The method of claim 25 , wherein the NFT comprises a disk shape.