Prof. Katsuaki SatoResearch: COE for Future Nano MaterialsEducation: Department of Applied Physics

Introduction to Optoelectronics1st Lecture: Optoelectronics in your neighborhood

Graduate School of EngineeringShort Term Education Program for Foreign Sudent

What do you imagine when you hear the word “opto-electronics”?

• Opto-electronics is a word combining optics and electronics, mainly used in Japan.

• American people prefer to use a term “optronics” or “electro-optics”.

• This academic field covers broad concepts involving light emitting devices and elements, information displays, image pickup devices, optical storages, optical communications, remote sensing systems and so on.

Why optical fiber can transmit light so far away?

• Structure of optical fiber• What is the total reflection?• How far can the fiber transmit light?• What are physical reasons of light attenuatio

n?– Long wavelength attenuation– Short wavelength attenuation– Optimum wavelenth

Can you tell how many kinds of displays are found in the market?

How many kinds of optical disks do you know?

• Read-only memory (ROM) type• Direct read after write (DRAW) or Write-once

type• Rewritable (RW) or Random access memory

(RAM) type• CD, MD, MO, DVD, BD, HD-DVD

Components of opto-electronics

• Light emitting diodes (LED)• Laser diodes (LD)• Why and how these diodes emit light?• To answer the question we need to understan

d; – diodes– semiconductors– pn junctions

Solid state physics underlying these semiconductor devices is necessary

Integrated optical circuit (IOC)

• integrated optical circuit (IOC) :A circuit, or group of interconnected circuits, consisting of miniature solid-state optical components on semiconductor or dielectric substrates. Note: IOC components include light sources, optical filters, photodetectors, and thin-film optical waveguides

http://www.atis.org/tg2k/_integrated_optical_circuit.html

Optoelectric integrated circuit (OEIC)

• Technologies for integrating optoelectronic devices and electronic circuitry

• Classified as either hybrid or monolithic• None of these technologies is fully developed,

but limited hybrid integration is available commercially.

http://web.mit.edu/fonstad/optochip/opto.home.html

Quiz• Please answer briefly the following questions in the sheet distributed. This

is to establish an optimal educational program for this class. The answer does not affect your final rating.

• Question 1 Can you tell a range of wavelength (in nm) of visible light?

• Question 2Laser is an abbreviation of a word string. Spell it out.

• Question 3 What is the difference between LED and LD?

• Question 4What is the difference between CD-R and CD-RW?

• Question 5Please explain how the light is transmitted through optical fiber.