1. OEIC LAB National Cheng Kung University 1 Ching-Ting Lee Institute of Microelectronics, Department of Electrical Engineering, National Cheng Kung University Integrated LiNbO 3 Electrooptical Electromagnetic Field Sensor

2. OEIC LAB National Cheng Kung University 2 Outline Introduction Principle and Configuration Experiments and Discussions Conclusions

3. OEIC LAB National Cheng Kung University 3 Application of electromagnetic wave Introduction Introduction

4. OEIC LAB National Cheng Kung University 4 Integrated LiNbO 3 Electrooptical Electromagnetic Field Sensor with Micro Multi-antenna Multi-annular antenna Laser diode Spectrum analyzer x y z Photodetector LiNbO 3 crystal Single-mode fiber Matching resistance SiO 2 buffer layer Polarization maintaining fiber AZ4260 buffer layer Mach-Zehnder modulator

5. OEIC LAB National Cheng Kung University 5 Mach-Zehnder modulator LiNbO 3 substrate Modulator electrode Output waveguide Input waveguide Principle Principle

6. OEIC LAB National Cheng Kung University 6 Ti-diffusion Waveguide Modulator electrode Z-cut LiNbO 3 substrate r 33 = 31  10 -12 m/V  : optical phase L: length of electrode : wavelength d: gap between electrodes Y Z X Buffer layer LiNbO 3 Crystal’s Electro-optic effect

7. OEIC LAB National Cheng Kung University 7 Vi V optical output intensity ½ Amplitude modulation applied voltage modulator voltage t optical output signal electrical signal optical signal

8. OEIC LAB National Cheng Kung University 8 Result 4V On-off extinction ratio is 25.6dB V  is about 4V

9. OEIC LAB National Cheng Kung University 9 Integrated LiNbO 3 Electrooptical Electromagnetic Field Sensor with Micro Multi-antenna Multi-annular antenna Laser diode Spectrum analyzer x y z Photodetector LiNbO 3 crystal Single-mode fiber Matching resistance SiO 2 buffer layer Polarization maintaining fiber AZ4260 buffer layer Mach-Zehnder modulator

10. OEIC LAB National Cheng Kung University 10 load 30mm 20mm 12mm 14mm 10mm 0.2mm Experiments and Discussions Experiments and Discussions Configuration of multi-annular antenna HE S

11. OEIC LAB National Cheng Kung University 11 Simulated resonant frequency of multi-annular antenna S 11 1.34 5.02 2.73 Frequency (GHz) Return loss (dB) 0 1 2 3 4 5 6 0 -5 -10 -15

12. OEIC LAB National Cheng Kung University 12 Advantages To obtain the frequency information To avoid the influence of the coaxial cable Microminiaturize

13. OEIC LAB National Cheng Kung University 13 Emitter (Horn antenna) E D=3m Test sensor Anechoic chamber (500MHz to 6GHz) Laser diode Photodetector Spectrum analyzer Signal generator

14. OEIC LAB National Cheng Kung University 14 load 30mm 20mm 12mm 14mm 10mm 0.2mm Experiments and Discussions Experiments and Discussions Configuration of multi-annular antenna HE S

15. OEIC LAB National Cheng Kung University 15 Simulated resonant frequency of multi-annular antenna S 11 1.34 5.02 2.73 Frequency (GHz) Return loss (dB) 0 1 2 3 4 5 6 0 -5 -10 -15

16. OEIC LAB National Cheng Kung University 16 Sensitivity factor S f E(V/m)  S f  V output (V) 1.4 2.8 5.2

17. OEIC LAB National Cheng Kung University 17 The sensitivity of the sensor Average minimum detectable field intensity 2.24mV/m Load H E-null configuration E

18. OEIC LAB National Cheng Kung University 18 Experimental Measurement of Electromagnetic Source Azimuth Using Electrooptical Electromagnetic Field Probe Vertical view 90 o 60 o Y X Z Axis of sensor probe Lateral view 60 o Sensor

19. OEIC LAB National Cheng Kung University 19 Probe Sensor 2 Sensor 3 Schematic diagram of the electrooptical electromagnetic field probe system Spectrum analyzer Photodetector Sensor 1 Laser diode

20. OEIC LAB National Cheng Kung University 20 Signal intensity (dBm) Directional sensitivity pattern at 2.8 GHz E H S H  

21. OEIC LAB National Cheng Kung University 21  The response bandwidth of electromagnetic field sensor is successfully superposed by integrating micro multi-antenna. This is demonstrated that the center frequencies of response spectrum can be controlled by designing micro multi- antenna.  When the sensor probe axis was pointed toward the electromagnetic radiation source, the highest sensitivity was obtained. The variation of the sensitivity is within about  0.4 dB with rotating the probe around its axis. By using the electrooptical electromagnetic field probe system, the azimuth of the electromagnetic radiation source can be measured. Conclusions

22. OEIC LAB National Cheng Kung University 22 Thank you!