集成光电子器件及设计 - 光学微腔结构设计与应用

第8章

光学微腔:

结构设计与应用集成光电子器件及设计2Microring

resonators:

structures

&

designs

Structure

Coupling

region

Directional

coupler:

straight

&

bent

DC

Vertical

coupler

MMI

coupler

MZI

coupler

MRR

coupler

Bending

section:

corner

bending

&

arc

bending

Cascaded

structures

Performances

High

Q‐factor

Large

FSR

(ultra‐small

bending

radius)

Large

tunable

wavelength

range

Suspended

cavityStructure

2x2

coupler

+

feedback:

2x2

coupler：

Directional

coupler

MMI

coupler

MZI

couplerFeedback

MRR

coupler

Arc

bending

Race‐track

Corner

bending

34With

directional

couplersEnhance

the

coupling

ratio.

5With

directional

couplersThe

small

gap

is

not

easy

to

fabricate.6With

directional

couplersEnhance

the

coupling

ratio.

7From

JJ

Hu

(MIT).

With

bent

directional

couplers

Compact

footprint

Low

loss:

w/o

transition

loss8With

vertical

couplerEasy

control

for

the

coupling

ratio;

Avoid

any

crossing

for

a

microring

array;

But

need

more

fabrication

processes;

9With

MMI

couplers2x2

MMI

couplers:Easy

fabrication.150μm10InputdropThroughaddWith

MMI

couplersTapered

MMI

couplers:

Easy

fabrication.

OUT#1

OUT#2

IN#1

Tapered

MMI

IN#2Output

Power(dBm)Output

Power(dBm)Normalization

PowerNormalization

PowerOutput

Power(dBm)Output

Power(dBm)-40110.60.40.20.00.81.0012345Angle

(°)Port

#2_1530nmPort

#1_1530nmPort

#2_1535nmPort

#1_1535nm0.60.40.20.00.81.003451530nm1535nmWith

MMI

couplers

0

-5

-10

-15

-20

-25

-30

-35153015311532153315341535Wavelength

(nm)Angled

MMI

couplers：Varying

the

coupling

ratio

-10

-15

-20

-25

-30

-35

-40153015311532153315341535Wavelength

(nm)1

2

Angle

(°)

-45-15-20-25-30-35153015311532153315341535Wavelength

(nm)-27.5-32.5

-7.5-12.5-17.5-22.51530

1531

1532

1533

1534

1535Wavelength

(nm)feedbackline12With

MZI

couplersMZI

couplers:Large

quasi‐FSRwDCwco11’22’LTPLTPLDCG

3’

3R~2μm

4’

42μm(a)Transmission

(dB)

0

-5-10-15-20-25-30152015401600162013

1560

1580Wavelength

(nm)(c)Coupling

Coefficient

k

Tthru

(dB)

Tdrop

(a.u.)

1.4951.49514With

MRR

couplers1.51.551.61.65

10.51.5

01.45

11.51.65

01.45

10.51.51.505

10.5

01.5

1.505

1.550.5

01

1.55

1.6Wavelength

λ

(nm)A

C

k(0)12'k(0)120.5

B

0

1.45@Thru

port

1.6

1.65@Drop

port

Coupler

#1

Coupler

#0

2

1

1′

121′2′R1R2Thru

DropInput

Ring

#1

2′

Ring

#215With

corner

bending16

With

micro‐diskHow

to

remove

the

multimode

effect?

Coupling

region

Lateral

coupling

(straight

&

bent

DC)

Vertical

couplingBending

section:

arc

bendingRemove

the

multimode

Whisper

gallery

modePhase‐matching

condition17Q‐value/alphaXC9/Research/SubwavelengthMicrodisks.html18环形谐振器的级联形式19More

forms

for

ring‐resonators20Synthesize

the

spectral

responses21Applications

of

micro‐cavities.

Optical

filters;

Optical

Switch;

Optical

modulators;

Laser;

Nonlinear

optics;

Optical

sensors;

22Applications

of

ring‐resonators:

optical

modulatorLipson’s

group

at

Cornell

Univ.

Nature

Photonics

4,

518

‐

526

(2010)

Optical

switch

23Prog.

Phys.

75

046402,

2012

24Enhanced

optical

force

in

a

resonatorThe

nanoscale

resonators

developed

at

Cornell

can

exert

relatively

strong

forces

on

tiny

particles,

leading

the

way

to

important

advancements

in

MEMS

and

MOMS

systems.

/nanoscale‐light‐resonator/13401/25Raman

laser

(silicon)Intel:

Nature

Photonics

1,

232

‐

237

(2007)

26Silicon

hybrid

laser

based

on

ringsBowers

group

at

UC

Santa

Barbara;Roel

Beats