1. Polymer Microrings Integrated With Thin Film InGaAs MSM Photodetectors For Sensor-On-A-Chip Applications
Sang-Yeon Cho
Electrical and Computer Engineering
Fitzpatrick Institute for Photonics
Duke University

2. Chip Scale Sensory Systems with Integrated Active Optical Components
Integrated Active Optical Components (Optical Source, Photodetectors)
Chemically Selective & Highly Sensitive Microresonator Sensor Arrays
Stability in Optical Alignment and Polarization

3. Background: Microresonators (Circulating & Transmitted Power vs Phase Shifts)

4. Four Port Polymer Microresonators (Through Port vs Drop Port)
Fabricated SU8 microring with 100 mm radius, 1 mm directional (straight) coupling section

5. Polymer Orthogonal Microdisk Sensors
Radius= 100 mm with 10 mm straight coupling section
SU-8 waveguide = 2 mm wide and 1.5 mm thick

6. Orthogonal Microresonators (Field Configuration and Output Characteristics)

7. Measured and Calculated Output of the Fabricated Microdisk Sensor
The measured mode spacing of the microdisks was 2.28 nm between
1545nm and 1565nm in the output spectrum
(dots: measured spectrum, solid line: calculated)

8. Resonant Wavelength Shift in Orthogonal Microresonator Sensors
neff= 1.500
neff= 1.505
neff= 1.510
t1=t2=0.9, a=0.99, and, R=100 mm

9. Resonant Wavelength Shifts in the Microdisk Sensors for Glucose Sensing
Glucose concentrations in DI water
(1.10 wt%, 1.82 wt%, 3.03 wt%, 5.75 wt% and 6.96 wt% )
The estimated sensitivity : 0.12 [nm/wt%]

10. Fabricated Polymer Microring Integrated with Thin Film InGaAs MSM PD
50 mm by 50 mm active area
1 mm thick
SU8 Microring
Radius= 100 mm with 10 mm straight coupling section
SU-8 waveguide
2 mm wide and 1.5 mm thick

11. Spectral Response Measurement Setup

12. Measured Spectral Response of the Fabricated Microring and Integrated Thin film MSM PD
The measured and calculated spacing in the resonant peaks
near l=1557nm are 2.36 nm and 2.46 nm, respectively.

13. Conclusions
Polymer microresonators have been fabricated and characterized.
Orthogonal SU8 microdisk sensors have been fabricated and tested with different glucose concentrations.
Polymer microring resonators integrated with thin film MSM photodetector demonstrated for chip scale sensor applications.
Measured photocurrent from the integrated thin film MSM photodetector were in good agreement with the spectral response of the microring resonator.