Third Order Universal Filter Using Operational Transresistance Amplifier

1. Third Order Universal Filter Using Operational Transresistance Amplifier A Multimode Interference Star Coupler with S-Bend Waveguide :By S. K. Raghuwanshi , SantoshKumar* Photonics Lab, Department of Electronics Engineering Indian School of Mines, Dhanbad-826004 Jharkhand, India.

2. Flow of Presentation: • Introduction • Beam Propagation Method • Results and Discussion • Conclusion • References

3. Introduction • Today multimode interference (MMI) Star couplers are more popular in the design of integrated optical circuits due to its advantages such as superior performance, excellent tolerance to polarization and wavelength variations, and compactness, insensitivity to polarization, and large bandwidth. • The planar waveguide optical couplers are of prime importance in optical communication and optical signal processing system. • S. K. Raghuwanshi, Santosh Kumar, V. Kumar, and D. Chack, “Propagation Study of Y-branch having inbuilt Optical Splitters and Combiner using Beam Propagation Method,” Progress In Electromagnetics Research Symposium, Moscow, Russia, 19-23 August, 2012.

4. Contd… • MMI works on the principle of Self-imaging Principle. • The principle can be stated as follows: Self-imaging is a property of multimode waveguides by which an input field profile is reproduced in single or multiple images at periodic intervals along the propagation direction of the guide. • The MMI technology main drawback is that couplers tend to be large if we are trying to obtain low loss and high accuracy.

5. Contd… • Figure 1: Layout of (a) MMI Coupler (b) MMI star coupler. • Santosh Kumar, S. K. Raghuwanshi, “Analysis of step discontinuities in rectangular MMI coupler by beam propagation method,” Proceeding of IEEE International Conference on Optical Engineering 2012, pp. 157-163, July 26-28, 2012, VTU, Belgaum, India.

6. Contd… Figure 2: For the thin waveguide there is only one allowed mode, which occurs near . Figure 3: The thick waveguide supports both even and odd modes. • S. K. Raghuwanshi, Santosh Kumar, “Step discontinuity analysis in an asymmetric single mode thin planar slab taper optical waveguide” i-manager’s Journal on Electronics Engineering (JELE), vol. 2, no. 2, pp. 43-48, Dec 2011-Feb 2012.

7. Beam Propagation Method • The beam propagation method (BPM) is the most popular and powerful numerical technique for modeling of guided wave photonic devices and most commercial software for such modeling are based on it. • To date numerous algorithms for BPM have been proposed and successfully applied to a very wide class of dielectric optical waveguide structures. • In this paper, we have analyzed theMMI star coupler by BPMhaving step discontinuity between thin planar slab waveguide with wide thick planar slab waveguide.

8. Results and discussion Figure 4: Plot of region of interest vs. length of wide waveguide

9. Contd… Figure 5: Plot of region of interest vs. revised length of wide waveguide

10. Contd… Figure 6: 2-D simulation with four S-bend output waveguide

11. Contd… Figure 7: 2-D Plot of optical field propagation, output field profile at fixing ,output field profile at fixing and 3-D plot of optical field propagation for the case of (a) - (d) respectively.

12. Contd… Figure 8: Output field profile at fixing

13. Contd… Figure 9: Power overlap Integral with fundamental mode.

14. Conclusion • The power loss found to be more for wide angle S-bend output waveguide. The loss occurs in the output waveguide with less angle and wide angle are 44% and 52 % respectively. • This is due to splitting of light into many parts and it may no longer remains guided. • The main advantages of star coupler are that light is guided at the output and there is a less substantial loss in the MMI star coupler compared to the existing simple MMI coupler. • The power distribution over the length are non-uniform due to the odd/even mode distribution.

15. References J. J. Wu, “A multimode interference coupler with exponentially tapered waveguide,” Progress In Electromagnetics Research C, vol. 1, pp. 113–122, 2008. Lucas B. Soldano and Erik C. M. Pennings, “Optical Multi-Mode Interference Devices Based on Self-Imaging: Principles and Applications,” Journal of lightwave technology, vol. 13, no. 4, april 1995. M. D. Feit and J. A. Freck, Jr., “ Light propagation in graded-index optical fibers,” Appl. Opt., vol. 17, pp. 3990-3998, 1978. J. Yamauchi, J. Shibayama, and H. Nakano, “Beam Propagation method using Pade approximant operators,” Trans. IEICE Jpn., vol. J77-C-I, pp. 490-494, 1994. G.. R. Hadley, “Wide-angle beam propagation using Pade approximant operators,” Opt. Lett., vol. 17, pp. 1426-1428, 1992. Hongzhen Wei, Jinzhong Yu, Zhongli Liu, Xiaofeng Zhang, Wei Shi, and Changshui Fang, “Fabrication of 4×4 tapered MMI coupler with large cross section,” IEEE Photonics technology letters, vol. 13, no. 5, May 2001. G. R. Hadley, “Transparent boundary condition for beam propagation method,” Opt. Lett., vol. 16, pp. 624-626, 1992. G.. R. Hadley, “ A multistep method for wide angle beam propagation,” Integrated Photon. Res., vol. 17, pp. ITu 15-1, pp. 387-391, 1993. S. K. Raghuwanshi, “Comparative study of asymmetric versus symmetric planar slab dielectric optical waveguides,” Indian Journal of Physics, vol. 84, no. 7, pp. 831-846, 2010.

16. References Santosh Kumar, S. K. Raghuwanshi, “Analysis of step discontinuities in rectangular MMI coupler by beam propagation method,” to be presented to IEEE International Conference on Optical Engineering 2012, 26-28 July, 2012, VTU, Belgaum, India. N. TalebiandM. Shahabadi, “Application of generalized multipole technique to the analysis of discontinuities in substrate integrated waveguides,” Progress In Electromagnetics Research, vol. 69, pp. 227–235, 2007. S. K. Raghuwanshi, Santosh Kumar, “Step discontinuity analysis in an asymmetric single mode thin planar slab taper optical waveguide” i-manager’s Journal on Electronics Engineering (JELE), vol. 2, no. 2, pp. 43-48, Dec 2011-Feb 2012. N. S. Lagali, M. R. Paiam, R. I. MacDonald, K. Worhoff, and A. Driessen, “ Analysis of generalized Mach-Zehnder interferometers for variable ratio power splitting and optimized switching,” J. Lightwave Technol., vol. 17, pp. 2542-2550, Dec. 1999. M. Koshiba and Y. Tsuji, “A wide-angle finite element beam propagation method,” IEEE Photon. Technol. Lett., vol.8, pp. 1208-1206, 1996. P. L. Liu and B.J. Li, “Study of form birefringence in waveguide devices using the semivectorial beam propagation method,” IEEE Photon. Technol. Lett., vol. 3, pp. 913-915, 1991. Y. Chung and N. Dagli, “Assessment of finite difference beam propagation,” IEEE J. Quantum Electron, vol. 26, pp. 1335-1339, 1990. L. Thylen, “The beam propagation method: An analysis of its applicability,” Opt. Quantum Electron, vol. 15, pp. 433-439, 1983.

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