Challenges in Teaching

and Research in Physics:

An Experience

A Day in your life

Good MorningGood Morning

Good NightGood Night

The Fruits of Science, Technology,

Engineering & Mathematics (STEM)

Berkeley

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EM Wave

E=mc2MIT

CambridgeCaltech

Oxford

Stanford

UM

Relativity

WWW

GPRS

The Future

Introduction – why am I here?

� This is not a motivational talk…….

� I’m not a professional motivator !!

� Nor am I here to lecture you how to TEACH….

� All of us have gone through the

training/process/experience

THE BEST TEACHER IS EXPERIENCE – ALLOW

ME TO SHARE SOME OF MY EXPERIENCES

Background

� Doctor of Philosophy (PhD) - MMU

� Optical Engineering

� Masters Science - UM

� Physics

� Bachelor Science (Hons) 1st Class - UM

� Physics

- Has 16 years of teaching experience in Private Institution

of Higher Learning

Background– subjects taught

� Undergraduate level

� Field Theory & Circuit Theory, Electromagnetic

Theory, Applied Electromagnetic Theory,

Optoelectronics and Optical Communication,

Microelectronics and Semiconductor Materials ,

Optics, Oscillation and Wave

� Postgraduate level

� Optical Communication, Fundamentals of

Modern Optics, Optical Waveguide, Electromagnetic

Interference

Importance of STEM

� STEM education plays an important role in socio-

economic development

� Workforce well trained in STEM is the key to new

inventions and product development

� Interest in STEM among school and university students

has been on the decline

� severe impact on country’s development and growth;

aspiration to be developed nation by 2020

Importance of STEM

� Malaysia needs 60% of school and university students

pursuing STEM for strong socio-economic development

� But, less than 30% of school and university students are

pursuing STEM now

� Interest in STEM is dwindling fast in schools and

universities

The Mind

� The mind is one of the most important ingredient for learning

� Basically, there are two types or combination of both:

� Inquiring mind – very curious and always looking for answers to many unanswered questions around us

� Creative mind – able to use or adapt with what is available, to produce something useful for mankind

The Mind

� Young minds need to be attracted to STEM with new

approaches

� fuel curiosity and creativity with interesting learning

experience through all five senses

Physics ?

� has something to do with all aspects of life both living and

non living - study of the laws of nature and behaviour of the

universe

� interesting, vast, mathematical and experimental

� becoming increasingly interdisciplinary - understand and

solve a wide range of problems confronting society

� learning physics helps in developing critical thinking - how

to pose questions and how to solve problems

What is involved in understanding

physics?

� elements are often invisible - careful observation and

analysis of behaviour required

� Without motivating the student, without provoking

thought and curiosity to learn the topic, little will actually

be understood about physics – VERY CHALLENGING

Overcoming the Challenges

� Listen to students

� Learn what they are thinking/learn how they think – by

providing problems to be solved or assignments to be

presented

� Students will reveal their poorly understood

concepts/formulas/ their misconceptions

� Understand students’ difficulties and confusions

� Improve on describing the concepts

Describing the Concepts

� Use multiple representations (words, graphs, drawings,

equations) of a physical situation and understand the

relationships among them

� Relate mathematical concepts to their physical meaning

and construct mathematical representations of physical

concepts

� Hands-on approach to visualize a phenomenon –

experiments, projects

� Use ICT technology to aid description of concepts –

video, physlets, animations

Teaching Physics

An Experience - examples

17

Concepts in Electromagnetics – how

to explain concepts• The concept in electromagnetics is provided by the

Maxwell equations:

t

BE

∂

∂−=×∇

rrr

vD ρ=⋅∇rr

0=⋅∇ Brr

Et

EH σε +

∂

∂=×∇

rr

• Use suitable methods to explain - allowing students

to visualize/relate the physical phenomenon

• The most effective way is to conduct simple experiments or even hand gestures

Concepts in Microelectronics & Semiconductor

Materials – how to provide overall idea of process

� In order to appreciate the

course better, a brief video

introduction of the

processes in

semiconductor industry

was shown

� Audio-visual experience will help in learning process

Concepts in Optics – how to ensure concepts

are understood by students

� Group assignment – 2 in a group

� Topic: Application of optics in the industry

� Presentation of assignment by each group –

20 minutes each

Content of assignment (min 10 pages)

� History of instrument

� Basic working principle

� Application

� Advantages/disadvantages

- Have a Q&A session opened to

all so that teachers/students can

explain and at the same time

think

OUR SMALL CONTRIBUTION

FOR THE SOCIETY TOWARDS

LEARNING STEM

Science Fair

� Science Fair @ UTAR drew hundreds of inquisitive young minds from secondary schools from all over Perak in a bustling affair held at Heritage Building at UTAR Perak Campus from 11 to 12 July 2013.

� R&D Exhibition at UTAR PetalingJaya Campus on 6 and 7 July 2012 to cultivate students' interest in science and research.

Symposium on Science Education

Objectives:

� To provide a platform for Science

teachers/educators to discuss

and explore new, innovative and

effective teaching methods in

Science education.

� To inculcate innovation in the

teaching of Science education

which will in turn, cultivate the

interest of students towards

pursuing Science related areas of

study.

� To provide networking

opportunities for Science

teachers/educators from various

schools, colleges and universities.

The one-day Symposium will be co-

organised by the UTAR and other

institution such as MTSF, MPN and

etc., scheduled on 23 August 2014

at the UTAR Perak campus in

Kampar, Perak. – Admission is FREE

KL Engineering Science Fair 2014

Optical Fiber and its Applications

24

The Research

25

INTRODUCTION

• a flexible and transparent medium made of glass or

plastic

• functions as a waveguide, or “light pipe” to transmit light

between two ends

• widely used in optical fiber communication, optical

sensors, fiber laser & amplifiers, illumination system,

etc.

26

• The fiber is made of a core

and a cladding, which can

be glass or plastic/polymer

materials.

• The buffer coating is made

of many different materials,

such as acrylic polymers,

polymide, and metals.

The bare optical fiber has a

slightly bigger diameter

than our hair

Optical fiber structure

27

Snell’s law states the relationship

between the refractive indices of

materials and the angle of

incidence and refraction as:

n1sinθ1= n2sinθ2

whereby n1 and n2 are the

refractive indices of different

materials while θ1 and θ2 are the

angle of incidence and refraction

respectively.

How does light propagate along a

fiber ?

28

Total Internal Reflection:• At angles of incidence greater than the critical angle the

light is reflected back into the originating dielectric media.

• Total internal reflection occurs when:

• n1 > n2• angle of incidence exceeds the critical angle• This is the basic mechanism by which light can propagate

down an optical fibre.

How does light propagate along a

fiber ?

29

Acceptance angle

• We have considered the propagation of light in an

optical fibre.

• But what is the amount of light which can enter the

optical fibre?

• Since only rays with a sufficiently shallow grazing

angle at the interface is transmitted, it is clear that

not all rays entering the fibre core will continue to

propagate down the fibre.

30

Numerical aperture

The relationship between the acceptance angle and

the refractive indices of the media leads to the

definition of numerical aperture NA:

NA = nosinθa = (n12 - n2

2)1/2

it should be noted that rays over the range of 0≤ θ1 ≤θa will be propagated within the fibre

31

Fiber Attenuation

There are four primary attenuation sources:

•material absorption

•scattering losses

•bending losses

•coupling losses

because of attenuation, light power gets smaller as

it propagates and as a result placing an upper limit

on the transmission distance and bit rate.

Analysis and Fabrication of

Integrated Fiber-based

Microlens

Introduction

• Optoelectronic devices enable today's global optical networks to allow massive data transmission

• In optoelectronic component assembly, the packaging accounts for 60 to 80 percent of current manufacturing expenses

• Improvements in packaging and processes are critical to reduce costs

• Some of the key active components in the optical network are source lasers and pump lasers

Packaging issues

• An understanding of the factors that influence their

yield, performance and reliability is essential to provide

solutions for lower packaging and production costs

Fundamental problem

• Launching of light from the optical devices into single

mode fibers (SMFs).

• Effects the performance and cost effectiveness of

optical device and systems

• Moving towards passive alignment, which requires

low loss and high misalignment tolerance

Coupling technique

• Discreet

• Utilises discreet optics such as ball lens, cylindrical lens, GRIN lens, etc.

• Miniature lens fabrication is expensive

• Integrated

• Utilises microlens which are integrated at the tip of the fibre.

• Types of microlens: hemispherical, conical, hyberbolic, wedge, etc.

• Relatively cheaper to produce

Analysis method

Coupling efficiency is determined using a simple method

called overlapped integral

where

and

+−

+−

=

yxyxyx

folR

yxik

w

yx

wyxE

,

22

2

,

224

1

2

,

,2

exp2

),(π

TE profiles of

Fiber and Laser

Diode

Gaussian

profile

A scheme consisting of multimode fibres in combination

with a hemispherically lensed fibre tip.

z

D L3 L2 L1 SMF

R

LD

SIF1GIFSIF2P1

eff

Integrated microlens

•In the proposed configuration, the hemispherically lensed

SIF2 functions as a collimator to align laser light into the GIF

fiber which in turn will function as a GRIN microlens to focus

the laser light

•The SIF1 has the function to optimise the numerical

aperture (NA) to be as low as the SMF at the output end of

the coupling configuration.

•SIF1 also makes it possible to maintain and align the GIF at

an appropriate distance from the SMF for focusing

purposes.

Integrated microlens: working

principle

Calculated ray trajectories within the fibre along the SIF2-GIF-

SIF1 as a function of the laser diode emission angle: θ , are

shown in the following figure:

-40

-30

-20

-10

0

10

20

30

40

0 500 1000 1500

Propagation distance in SIF2-GIF (µm)

Po

sit

ion

, h

(m

)

5deg 10deg 12deg

SIF2 GIF SIF1

θ = 12o

θ = 10o

θ = 5o

Propagation distance in SIF2-GIF-SIF1 (µm)

Integrated microlens: Results

Integrated microlens: Results

-10

-8

-6

-4

-2

0

2

4

6

8

10

-8 -6 -4 -2 0 2 4 6 8

Angle (deg.)

He

igh

t ( µ

m)

Sam ple A Sample B Sample C

Focusing properties of

the coupling scheme.

The rectangular region

indicated by the dashed

line represents the

domain for the specific

values of h and φ.

Analyses were

conducted at z = 65µm

at a wavelength of

1.31µm.

Integrated microlens: Results

Integrated microlens: Results

Other microlenses: Conical lens

• Fabricated by using an etching

method (HF solution).

• Cladding will etch at higher rate

than the core.

• The difference in etching rate

produces a conical shape at the

core region and a flat surface at

the cladding region.Scanning electron microscope (SEM)

photo of conical lens at the tip of SMF

(Faidz, Kenzo, & Teik, 2003).

Other microlenses: Conical lens

Fabrication and characterisation

of Long Period Optical Fiber

Sensors

Introduction

• Biosensor – a sensing tool to detect an analyte by

combining a biological component with a physiochemical

detector

• Important for clinical and point of care testing

• An optical biosensor uses light as a sensing tool to detect

an analyte

Introduction (continued…)

• Long Period Fiber Grating (LPFG)-based biosensor is an

optical sensing tool utilizing the long period grating to

detect biomolecules

• Its higher sensitivity and anti-interference ability for

response to chemicals and biochemicals as well as

biomolecules makes it a promising method in portable

sensoring

Theory of Long Period Fiber Grating

Period

Incident light Transmitted lightBroadband source

λ

Core Cladding

• LPFGs are based on codirectional couplings and periodic

modulation of the refractive index along the length of fiber.

• Under phase-matching conditions, the grating couples the

fundamental core mode to the discrete cladding modes

whereby the optical signal will be attenuated due to

absorption and scattering.

Detection method for LPFG

• Changes in the Analyte Refractive Index (ARI)

• Changes on the surface of the LPFG

• Changes in the thickness of the biofilm

• These changes affected the cladding’s effective index

which in turn changes the phase-matching condition of the

LPFG

Fabrication Setup using Electrical

Arcing for Periodically Tapered LPFG

SpectrometerLight

Source

ComputerMotorized stage with arc generator

Fiber Clamp Fiber Clamp with

slider

Tension meter

Weight

Fabrication of LPG is writing the grating on the cladding of the Fibre.

LPFG imaging from naked eyes to SEM

Gratings formation

123.84um

105.23um

4x Microscope

SEM

One grating

LPFG – notch formation

Wavelength (nm)

Att

enuat

ion (

dB

)

Changes of fiber transmission after arc-induced long period grating

-40

-35

-30

-25

-20

-15

-10

-5

0

156

01

56

0.8

156

1.6

156

2.4

156

3.2

156

41

56

4.8

156

5.6

156

6.4

156

7.2

156

81

56

8.8

156

9.6

157

0.4

157

1.2

157

21

57

2.8

157

3.6

157

4.4

157

5.2

157

61

57

6.8

157

7.6

157

8.4

157

9.2

158

0

Air

Water (RI=1.3351)

20% Glucose (RI=1.3603)

40% Glucose (RI=1.3845)

60% Glucose (RI=1.4099)

80% Glucose (RI=1.4356)

Characterization of LPFG – Refractive

IndexWavelength(nm)

Tra

nsm

issi

on

(dB

m)

Wavelength shift towards left

Characterization of LPFG –

Temperature

-35

-30

-25

-20

-15

-10

-5

0

30°c

50°c

70°c

90°c

110°c

130°c

150°c

Wavelength shift towards right

Tra

nsm

issi

on

(dB

m)

Wavelength(nm)

Characterization of LPFG – Strain

-40

-35

-30

-25

-20

-15

-10

-5

0

0g

10.8g (5.4cN)

15g (7.7cN)

20g (10.9cN)

25g (15cN)

Tra

nsm

issi

on

(dB

m)

Wavelength(nm)

Wavelength shift towards right

THE END