Dual Acousto-Optical Tunable Filter (AOTF)

University of California IrvineDavid TsengMentor: Rong HuangPI: Professor Henry Lee

Overview

Introduction of an AOTF– Application & Motivation

Construction of an AOTFExperimental results based on different fibers (SMF, PMF and DCF)Future work

Applications of an AOTF

Applicable to wavelength division multiplexing (WDM) in fiber optic communication network

For spectrometry applications: Broadband Infrared (BBIR) Tunable Camera Filter (TCF), Portable NIR Spectrometer, and Portable Optical Spectra Analyzer (POSA)

The Fashion of Frequency

In communicationsAM 0.300 MHz to 3 MHz FM 30 MHz to 300 MHz TV 50 MHz to 450 MHzCell Phone 850/900/1800/1900 MHz Cell WLAN 2 GHzWLAN2.4 GHz

Optical ~THz

Introduction of an AOTF---- Interaction principle

Jacket

Cladding

CorePhotonPhonon

Photon

Core

Introduction of an AOTF

Conditions for photon-phonon interaction to happen– Conservation of energy – Conservation of momentum

Specifications of its spectrum– It is narrow band, which means it only happens at certain

range.– It is a notch filter.– The resonator wavelength can be tuned electrically.– The depth of notches can be tuned electrically.

Introduction of an AOTF

OSALED

RF Generator

Stripped fiberPC

Construction of an AOTF -----Piezoelectric Transducer (PZT)

Source of Acoustic energyDegree of freedom and flexibility

Shear mode

Construction of an AOTF -----Piezoelectric Transducer (PZT)

Sheer Mode PZT

Compression

TensionLongitudinal Mode PZT

RF Generator

Stripped fiber

RF Generator

Stripped fiber

Construction of an AOTF----Experimental Setup

Construction of an AOTF ---- Experimental Setup

Method tried to increase its efficiency – Find a right range of its resonate frequency

• Optimize its shape (physical dimension)• Find right materials

– Self-heating problem• Cooling down system---heat sink

– The optimization of the materials in between• Super glue---easy to do but can’t stand long and high temperature• Solder---- not easy to do but better performance

Construction of an AOTF ---- Experimental Setup

Acousto-Optical Tunable Filter

Dual-sheer mode PZT setup

Experimental Results ---- SMF, PMF and DCF

1520 1540 1560 1580 1600-14

-12

-10

-8

-6

-4

-2

0

Tra

nsm

issi

on

(d

B)

Wavelength (nm)

y-polarized light x-polarized light

1587 1588 1589 1590 1591 1592 1593-14

-12

-10

-8

-6

-4

-2

0

Tra

nsm

issi

on (dB)

Wavelength (nm)

TE01 TM01

HE21

Future Work

Acoustic impedance matching network--- increase the acoustic efficiencyAOTF can be used to measure properties of different kinds of fibersThis notch filter can be converted into a band-pass filter.

Acknowledgements

Professor Henry Lee – Opportunity and inspiration and encouragement

Ph.D Student Rong Huang – PMF, Efficiency

Ph.D Student Fares Alhassen – Concepts, polarization

M.S. Student Alvin Wong – KLM model, characterization, OSA

IM-SURENSF