Design and Fabrication of Anti-Reflection Thin Films for Fiber Optic Communication Systems Advisors Dr. H. Masoudi Dr. E. Khawaja Dr. S. Ayub Group E Mansour Al-Hagwi Ahmed Afif Amjad Sindi Rayyan Al-Ghamdi King Fahd University of Petroleum and Minerals Electrical Engineering Department 19 May 2002

In This Presentation Introduction Fabrication of Thin Films Physical Vapor Deposition Physical Vapor Deposition Controlling the Thickness Controlling the ThicknessMeasurements Spectrophotometer Spectrophotometer Single Layer Anti-Reflection Film (SLAR) Design and Fabrication Design and Fabrication Results Results Double Layer Anti-Reflection Film (DLAR) Design and Fabrication Design and Fabrication Results Results Inhomogeneous Films Conclusion

Introduction Fiber Optic Incident Wave Reflected Wave (4.3%)Transmitted Wave (95.7%) Glass Air The aim of the project is to minimize the losses due to reflection

Introduction Fiber Optic Incident Wave No ReflectionTransmitted Wave (100%) Thin Film Glass Air

n0n0 n1n1 n2n2 Introduction Anti-Reflection Mechanism: Multi-Reflection Glass Film Air Destructive Interference Constructive Interference n1n1 Refractive index Thickness d Important Parameters of Thin Films Refractive index (n) Thickness of the film (d)

Physical Vapor Deposition Need of Vacuum Need of Vacuum Approaches Approaches Resistive Heating Electron Beam Controlling the Thickness Quartz Crystal Thickness Monitoring Quartz Crystal Thickness Monitoring Optical Thickness Monitoring Optical Thickness Monitoring Fabrication of Thin Films

Physical Vapor Deposition Resistive Heating Resistive Heating Apply voltage to the terminals High current will pass Temperature increases Material evaporates in a shape of a cone Small Boat Terminals Coating Material

Fabrication of Thin Films Physical Vapor Deposition Electron Beam Electron Beam High power Concentration on a small surface PocketFilament Electron Beam e-e-

Fabrication of Thin Films Controlling the Thickness Quartz Crystal Quartz Crystal Quartz crystal is fixed Substrate is rotating => Different positions => Different amounts of evaporant => Geometrical Factor (G) taluartz crysd on the qm depositeof the filThickness ubstrated on the sm depositeof the filThickness G

Fabrication of Thin Films Controlling the Thickness Optical Thickness Monitoring Optical Thickness Monitoring

Measurements Dual Beam Spectrophotometer Light Source Slit Grating Monochromator Sample Splitter Reflector Detector 2 Detector 1 Reference Beam Sample Beam

Single Layer Anti-Reflection Films Design of SLAR Fabrication of MgF 2 Film Resistive Heating Resistive Heating Quartz Crystal Thickness Monitor Quartz Crystal Thickness Monitor Film (n 1 ) Glass (n 2 =1.52) Air (n 0 =1) MgF 2 (n 1 =1.38)Film (n 1 =1.23)

Single Layer Anti-Reflection Films Results of MgF 2 Film R Experimental = 0.7% R Theoretical = 1.3%

Double Layer Anti-Reflection Films Design of Double Layer Film WO 3 (n 2 = 2) Glass (n 3 = 1.52) (n 0 = 1)Air NdF 2 (n 1 = 1.6) Fabrication of Double Layer Film Resistive Heating Resistive Heating Optical Thickness Monitor Optical Thickness Monitor Film 1 (n 1 ) Film 2 (n 2 )

Double Layer Anti-Reflection Films Results of Double Layer Film R Theoretical = 0.02% R Experimental = 0.5%

Inhomogeneous Films Microscopic view of inhomogeneous films (from literature) Region 1 Region 2 =>=>

Inhomogeneous Films Fabrication of CeO 2 Film Electron Beam Electron Beam Quartz Crystal Quartz Crystal Experimental Results R Experimental = 0.1%

Conclusion Uncoated Glass Single Layer FilmsDouble Layer Film Material_____MgF 2 CeO 2 NdF 2 + WO 3 Theoretical Reflectance (%) 4.3 Experimental Reflectance (%) 4.2 Improvement in Reflectance (%) _____ _____ ? ?

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