1. Photonic-chip-based RF spectrum analyzer Raphael Bouskila

2. 6/23/2016R. Bouskila2 Outline Introduction Introduction Waveguide Waveguide RF spectrum analyzer RF spectrum analyzer Conclusion Conclusion

3. 6/23/2016R. Bouskila3 Introduction

4. 6/23/2016R. Bouskila4 Waveguide Amount of nonlinearity dependent on intensity: Amount of nonlinearity dependent on intensity: Fiber core diameter: ~8-10 μm Fiber core diameter: ~8-10 μm –Effective area: ~50-80 μm 2

5. 6/23/2016R. Bouskila5 Waveguide Second problem: Dispersion Second problem: Dispersion –N.B. D = D WG + D mat

6. 6/23/2016R. Bouskila6 Waveguide What to do? What to do? Solution: Ridge (or rib) waveguide Solution: Ridge (or rib) waveguide

7. 6/23/2016R. Bouskila7 Waveguide High nonlinearity achieved via extremely high mode confinement High nonlinearity achieved via extremely high mode confinement –A eff : 2.61 μm 2 Low dispersion achieved by compensating D mat with D WG Low dispersion achieved by compensating D mat with D WG

8. 6/23/2016R. Bouskila8 Waveguide When they say “wide bandwidth,” they aren’t kidding: When they say “wide bandwidth,” they aren’t kidding:

9. 6/23/2016R. Bouskila9 RF spectrum analyzer Regular PSD: Regular PSD: RF spectrum: RF spectrum: Used to characterize sources and components; provides information about distortions and nonidealities Used to characterize sources and components; provides information about distortions and nonidealities

10. 6/23/2016R. Bouskila10 RF spectrum analyzer Typically done using expensive electronics Typically done using expensive electronics All-optical method preferred! All-optical method preferred!

11. 6/23/2016R. Bouskila11 RF spectrum analyzer

12. 6/23/2016R. Bouskila12 RF spectrum analyzer

13. 6/23/2016R. Bouskila13 Conclusion Advantages: Advantages: –Ultrawide bandwidth –Record-setting nonlinearity –Low dispersion Limitations: Limitations: –Material and fabrication costs –Dispersion could be minimized further

14. 6/23/2016R. Bouskila14 References [1] M. Pelusi et al. Photonic-chip-based radio- frequency spectrum analyser with terahertz bandwidth. Nature Photonics 3, 139-143 (March 2009). [1] M. Pelusi et al. Photonic-chip-based radio- frequency spectrum analyser with terahertz bandwidth. Nature Photonics 3, 139-143 (March 2009). [2] B. E. A. Saleh & M. C. Teich. Fundamentals of Photonics, 2nd ed. Wiley, 2007. [2] B. E. A. Saleh & M. C. Teich. Fundamentals of Photonics, 2nd ed. Wiley, 2007. [3] G. P. Agrawal. Nonlinear Fibre Optics, 4th ed. Academic Press, 2006. [3] G. P. Agrawal. Nonlinear Fibre Optics, 4th ed. Academic Press, 2006. [4] M. R. E. Lamont et al. Dispersion engineering of highly nonlinear As2S3 waveguides for parametric gain and wavelength conversion. Opt. Express 15, 9458–9463 (2007). [4] M. R. E. Lamont et al. Dispersion engineering of highly nonlinear As2S3 waveguides for parametric gain and wavelength conversion. Opt. Express 15, 9458–9463 (2007).