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TOPIC: OPTICAL DETECTOR APD
Optical Fiber Communication

STUDENT: NGUYEN THI HUYEN HOA
NGUYEN THI THU UYEN
NGUYEN QUOC PHUOC
HO DINH DUNG
LECTURER: TRAN THI KIEU

11/26/20

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Content

INTRODUCTION

SUMMARY: PN, PIN,APD
AVALANCHE PHOTODIODE

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Content

INTRODUCTION

SUMMARY: PN, PIN,APD

AVALANCHE PHOTODIODE

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INTRODUCTION
Optical Communication System

PN

Avalanche Photodiode
Photodiode

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Hình 1. Optical Communication System.
Nguồn: Internet.

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Content

INTRODUCTION

SUMMARY: Photodiode, PIN Photodiode
AVALANCHE PHOTODIODE

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SUMMARY
P-N junction

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SUMMARY
P-N junction

Etx
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SUMMARY
P-N junction

Forward Bias

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Forward Bias

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SUMMARY
Photodiode

Photon

Photodiode

Diode (P-N junction)

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SUMMARY
Photodiode

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SUMMARY
Photodiode

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SUMMARY
Photodiode

Disadvantage

Temperature
dependent device

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SUMMARY
PIN Photodiode

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SUMMARY
PIN Photodiode

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SUMMARY
PIN Photodiode

Most of the photon are absorbed in the intrinsic region

Most carriers are generated in the intrinsic region, because that can be much thicker than depletion region of a
p-n structure

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SUMMARY
PIN Photodiode

Core

Disadvantage

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Depletion region is expanded

Require large reverse bias voltage

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Content

INTRODUCTION

SUMMARY: Photodiode, PIN Photodiode
AVALANCHE PHOTODIODE

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AVALANCHE PHOTODIODE
What is the Avanlanche Photodiode ?

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It conver light energy in to electrical signal
Designed to operate in reverse bias condition .They use avalanche breakdown to give gain.

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AVALANCHE PHOTODIODE
Image about APD

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AVALANCHE PHOTODIODE
Structure of APD

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AVALANCHE PHOTODIODE
Avalanche Breakdown

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AVALANCHE PHOTODIODE
Working of APD
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AVALANCHE PHOTODIODE
Advantages and Disadvantages of APD

Advantages
Avalanche gain -> high sensitivity.

Disadvantages

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High operating voltage is required.
At high voltage -> noise is high.
Avalanche process means that output is no
linear.

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AVALANCHE PHOTODIODE
Application

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Laser range finder.
Speed gun.
Fast receiver modules for data communications.
High speed laser scanner.

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AVALANCHE PHOTODIODE
Parameters

PIN Photodiode

APD

Layers

+
+
P -I-N

+
+
P -π-I-N

Gain

<1

More gain provided

Amplifier requirement

Highly required

Required

Response Time

Very Less

More

Output current

Less output current

High output current

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Noises

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Photon noise
Shot noise (low)

Shot noise (high)
Thermal noise
Avalanche noise

Sensitivity

Less sensitivity

Highly sensitivity

Reverse Bias Voltage

Lower

Higher to breakdown voltage

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