Whispering-Gallery Mode Microlasers

Whispering-Gallery Mode Microlasers

— from microdisk resonator to square resonator

Huang Yong-Zhen (黄永箴) Institute of Semiconductor, State Key Lab on Integrated

Optoelectronics Chinese Academy of Sciences

报告提纲

I. 光学微腔及应用

II. 直连波导的微盘激光器

III. 正方形微腔激光器

IV. 集成的微腔激光器

2

Fabry-Pérot cavity：vertical-cavity surface-emitting lasers

• Whispering-Gallery mode microcavity: microdisk laser

• Photonic Crystal microcavity

K. J. Vahala, Nature vol.424, p. 839 (2003)

Microcavities

3

VCSEL-有源光缆光互连应用

(a)2003年服务器电缆；(b)2000年HP电缆；(c)

标准PCIe-x16电缆； (d)2007年有源光缆. 电缆传输距离2~3m,光缆传输距离100m 4

直调光子晶体激光器~fJ/bit数据传输

Nature Photon., vol. 7, p.569(2013) 5

Opt. Exp., vol.17, p.11107(2009) “Thresholdless nanoscale coaxial lasers”

Nature, vol. 482, p.204, 2012.

等离子激元纳激光器(金属层限制)

Nature mater., vol. 10, p. 110( 2011)

6

Nature Commun. DOI:10.1038/ncomms3822(2013)

Electrically driven nanobeam lasers

7

Whispering-Gallery Mode

L. Rayleigh，The problem of the whispering

gallery, Phil. Mag., 20, 1001(1910)

Echo-wall of Heaven Temple

Heaven Temple

St. Paul’s Cathedral

8

Total internal reflection

S. L. McCall et al, Appl. Phys. Lett., vol.60, 289 (1992), Electron. Lett.,

vol.28, p.1010(1992), Appl. Phys. Lett., vol.83, p.797(2003)

Optical microdisk lasers

a) Geometrical optics and b) wave optics

representation of a whispering gallery mode Adv. Matt., vol.25, p.707(2013)

9

Directional emission microdisk lasers

(d) Science, 280, 1556(1998); (e) Appl. Phys. Lett., 83, 710(2003), (f) IEEE Photon. Technol. Lett., 15,1330(2003)

Nature Photon., vol.4, p.182(2010) PNAS, 107, 22407(2010)

10

Droplet microlaser

Laser Photon Rev.，vol.7, p.60（2013）

11

L. Ge, et al, “Rotation-induced evolution of far-field emission

patterns of deformed microdisk cavities”, Optica, vol.2, p.323

(2015)

Rotation related far-field emission patterns 片上光学陀螺

10-13 ~6 rad/s 12

Microresonator frequency comb

Microresonator frequency comb optical

clock, Optica, vol.1, p.10(2014)

13

Light-trapping diamond waveguide for sensing

“Broadband magnetometry and

temperature sensing with a light-

trapping diamond waveguide”,

Nature Phys DOI:

10.1038/NPHYS3291(2015)

氮空位

14

PNAS,vol.111,p.E3836(2014)

Raman microlaser for detecting nanoparticles

15

Whispering-gallery microlaser in living cells

Nano.Lett.，15, 5647-5652(2015)

折射率1.60:1.375

半径5~10微米

NATURE PHOTONICS DOI:

10.1038/NPHOTON.2015.129

(2015)

16

报告提纲





17

Mode solution for 2D microdisk resonators

Mode field distribution in a 2D microdisk with a radius of R:

0

(1)00(1)

0

( , ) ( )exp( )

( )( , ) ( )exp( )

( )

z v

vz v

v

F r AJ nk r iv r R

J nk RF r A H k r iv r R

H k R

(1)' ' (1)

0 0 0 0( ) ( ) ( ) ( )v v v vJ nk R H k R J nk R H k R

Eigenvalue equation for calculating mode wavelengths and mode Q

factors:

Jv(x) and Hv(1)(x) are Bessel function and first kind Hankel function, for

TM and TE modes η = n and 1/n, respectively.

M. Hentschel et al, Phys. Rev. E 66, 056207 (2002). 18

WG mode field patterns in a circular resonator with a

diameter of 4.5 μm and refractive index of 3.2.

Superposition of TM18,3 and

TM15,4 with phase difference

of (a) π and (b) 0.

Analytical solution.

TM18,1 TM18,2 TM18,3 TM15,4

±

19

1540 1545 1550 1555 156010-5

10-4

10-3

10-2

10-1

100

Q = 6.7x104

Inte

nsity (

a.u

.)

Wavelength (nm)

Three ports

Four ports

5.36x103

Opt. Exp., vol.17, p.23010(2009), Semi. Sci. Techonol., vol.25, 105005(2010)

Mode coupling and directional emission for microdisk

1.40 1.45 1.50 1.55 1.6010

-6

10-5

10-4

10-3

10-2

10-1

100

101

1.49 1.4902 1.490410

-3

10-2

10-1

100

Inte

nsity (

a.u

.)

Wavelength (m)

(a)perfect microdisk

1.40 1.45 1.50 1.55 1.6010

-6

10-5

10-4

10-3

10-2

10-1

100

Inte

nsi

ty (

a.u

.)

Wavelength (m)

Symmetric

Antisymmetric

(b)

d

nO

R

Diameter 4.5μm microdisk connected a 0.6μm output waveguide

Radius 10μm microdisk connected three and four 2μm output waveguides

20

1530 1540 1550 1560 1570

-60

-50

-40

-30

-20

-10

45mA, 290K

Inte

nsi

ty (

dB

)

Wavelength (nm)

Rin= 0(a)

28.4dB

2.29nm

11.08nm

Unidirectional microdisk and microring laser

(radius 10 m)

J. Opt. Soc. Am. B, vol. 31, p.2773(2014) 21

22

2 4 6 8 10 12 14 16 18 20-15

-12

-9

-6

-3

0

3

6

9

Modulation Frequency (GHz)

Modula

tion R

esponse

(dB

)

12 mA

15 mA

18 mA

15.2 GHz

2 4 6 8 10 12 14 16 18 20-15

-12

-9

-6

-3

0

3

6

9

Modula

tion R

esponse

(dB

)


10 mA

15 mA

20 mA

13.0 GHz

Microring laser Microdisk laser

R = 15 μm, d = 7 μm, W = 2 μm R = 15 μm, W = 2 μm

(a)

Influence of carrier spatial hole burning and

diffusion on high speed modulation

Appl. Phys. Lett., vol. 104, 161101(2014)

Mode field pattern

23

Size limit for microdisk lasers with vertical semiconductor

waveguide-vertical radiation loss

1380 1400 1420 1440 1460 1480 1500-80

-60

-40

-80

-60

-40

-80

-60

-40

1380 1400 1420 1440 1460 1480 1500

0.62 nm

(c)

Wavelength (m)

R = 3.25 m

I = 3 mA

0.25 nm

(b) R = 3.5 m

I = 1.5 mA

Inte

nsity (

dB

m)

0.2 nm0.056 nm

R = 3.75 m

I = 1 mA

(a)3.0 3.5 4.0 4.5 5.0 5.5

0.0

0.5

1.0

1.5

2.0

Radius (m)

Th

resh

old

Cu

rre

nt

(mA

)

0

2

4

6

Thre

shold

Curr

ent D

ensity (

kA

/cm

2)

T = 288 K

1380 1400 1420 1440 1460 1480 150010

2

103

104

105

Mode B

Q

Wavelength (nm)

R = 3 m

R = 3.25 m

R = 3.5 m

R = 3.75 m

Mode A

Mode Q factors obtained by 3D FDTD

Threshold current versus disk radius

J. Opt. Soc. Am. B, vol.32, p.439(2015)

报告提纲





24

Triangle Square Octagon

Different whispering-gallery mode microlasers

IEEE J. Sel. Top. Quantum

Electron., vol.19, 1501808 (2013) IEEE Photon Technol

Lett, vol. 19, p. 963(2007)

Opt. Lett., vol.33, p.2170

(2008） IEEE Photon. J., vol.3,

p.756(2011) 25

Our SCI papers about square and microdisk resonators

JQE: IEEE J. Quantum Electron.; PTL: IEEE Photon. Technol. Lett.; OL: Opt. Lett.; APL: Appl. Phys. Lett.

COL: Chin. Opt. Lett.; JLT: J. Lightwave Technol.; OE: Opt. Exp.; EL: Electron. Lett., JAP: J. Appl. Phys. 26

2002 2004 2006 2008 2010 2012 2014 20160

2

4

6

8

10

SC

I P

ap

er

Nu

mb

ers

Year

JQE2

PTL+OL+COL+JQE

APL+JQE+PTL2+EL+JAP+JOSAB

JSTQE+El2+QE2+OE2

+APL+PJ+JOSAB+OEng

JLT+OL+PTL+OE

+SCI China

Square resonator

microdisk+microring

2D rectangular microresonator

reduced to three-layer slab waveguides in x and y-directions

W5

W4

W3

W2

W1

z

C4

-1 C4

C2

x

ys

y

sd

''

sd

'

sx

W. H. Guo, et al, IEEE J. Quantum Electron., vol. 39, p.1563 (2003)

Y. D. Yang, et al, IEEE J. Quantum Electron., vol. 43, p.497(2007)

Fz (p, q) = Fzxp(x) Fzyq(y)

2

0

2

1

22 )1( kn 2

0

2

1

22 knyx

cos( ) / 2

cos( / 2 )exp[ ( / 2)] / 2

cos( / 2 )exp[ ( / 2)] / 2

x x

p

zx x x x

x x x

x x a

F a x a x a

a x a x a

cos( ) / 2

cos( / 2 )exp[ ( / 2)] / 2

cos( / 2 )exp[ ( / 2)] / 2

y y

q

zy y y y

y y y

y y b

F b y b y b

b y b y b

tan( / 2 )

tan( / 2 )

x x x x

y y y y

a

b

For TE mode = n1

2/n22

For TM mode = 1, v = x, y

27

Y. D. Yang, et al., IEEE J. Quantum. Electron., 43, 497, 2007.

2.0 2.1 2.2 2.3 2.4175

180

185

190

195

200

205

102

103

104

Qu

alit

y fa

cto

r

Fre

qu

en

cy (

TH

z)

Length a (m)

Mode A

Mode B

175 180 185 190 195 200 20510

-4

10-3

10-2

10-1

100

101

Mode B

No

rma

lize

d in

ten

sity

Frequency (THz)

a = 2 m

2.16 m

2.4 m

Mode A

High Q mode has field distribution anti-symmetry to the diagonals of resonator

High Q mode with small vertex radiation loss

Field patterns of electric field component

Ez obtained by FDTD simulation for the

mode A with the length of (a, d) 2 m,

(b,e) 2.16 m, and (c,f) 2.4 m.

Mode A

Mode B

28

Analytical electric filed patterns for (a) TM6,8, (b) TM5,9, and (c) TM4,10 in square

resonator with side length 2.5 µm and refractive index 3.2

Electric field patterns for (a) TM6,8and(b) TM4,8 in square

resonator with side length 2.5 µm and a output waveguide

Mode field pattern for square resonators

Light ray analysis IEEEJ.Quantum Electron. vol.39,

p.1106(2003), vol.46,p.414(2010)

29

InP

AlGaInAs QWs

SiO2

SiNx

BCB

P-electrode

N-electrode

Etching BCB Opening p-electrode

window

Forming

electrodes

Planized by filling BCB Photolithography and

ICP etching

Fabrication technique process

30

Square microlasers with different output waveguides

0 10 20 30 40 500

100

200

300

400

500

y

x

z

PMMF

PSMF×3

Voltage

I (mA)

Po

wer

(μ

W)

0.0

0.3

0.6

0.9

1.2

1.5

1.8V

olt

age

(V)

(a)

1520 1530 1540 1550 1560 1570 1580 1590

-70

-60

-50

-40

-30

-20

-10

40

32

24

16

8

B

Wavelength (nm)

Inte

nsi

ty (

dB

m)

Cur

rent

( m

A)

(a) A

Powers coupled into MMF and SMF versus CW current, and lasing spectra at 8, 16, 24, 32

and 40 mA for microlaser with side length 16m and 2m wide vertex output waveguide.

Sci China-Phys Mech Astron vol. 58, 114205(2015)

1520 1530 1540 1550 1560 1570 1580

-70

-60

-50

-40

-30

-20

-10

Inte

nsi

ty (

dB

m)

Wavelength (nm)

24 mA

SMSR:41 dB

91

92

93

94

95

96

97

98

99

100

p+

q

IEEE J. Quantum Electron., vol. 50, p.981(2014)

2 2

, 2 / [( 2) / ] [( 2) / ]p q x yan p q

31

1.0 1.2 1.4 1.6 1.8 2.0

8.0x104

1.6x105

2.4x105

3.2x105

4.0x105

Width of output waveguide (μm)

Mo

de Q

facto

r

TEo,(52,56)

TEo,(51,55)

TEo,(50,54)

TEo,(49,53)

(b)

1.0 1.2 1.4 1.6 1.8 2.0

2.0x104

4.0x104

6.0x104

8.0x104

TEo,(52,56)

TEo,(51,55)

TEo,(50,54)

TEo,(49,53)

Width of output waveguide (μm)

Mo

de Q

facto

r

(a)

Mode Q factors versus the output waveguide width

at (a) g = 0 and (b) g = 2 cm-1 in square resonator

with the side length of 17.8 m. a = 17.8 m and w = 1.8 m

Single mode square microlaser

32

Square microlaser with the side length

of 17.8 m and the output waveguide

width of 1.4 m

Based on the redshift rate, the

temperature rise of 81 K is obtained from

5 to 65 mA and the practical laser

temperature is about 379 K at 65 mA.

Opt. Exp., vol. 23, p.27739(2015)

Single mode square microlaser

33

Transverse mode wavelength interval modulated by refractive index distribution

10 15 20 25 30

0.3

0.6

0.9

1.2

1.5

1.8

Δλ

(nm

)

a (μm)

-10 -5 0 5 10

-10

-5

0

5

10

-1

-0.5

0

0.5

1

(a)

-10 -5 0 5 10

-10

-5

0

5

10

-1

-0.5

0

0.5

1

(b)

Mode wavelength intervals versus Δn for square resonators with a = 20 μm, wg =

1.5 μm, W = 2 μm, and a = 30 μm, wg = 2.5 μm, W = 4 μm.

-5 -4 -3 -2 -1 0 1 2 3 4 50.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4 a = 20 m, W = 2 m

a = 30 m, W = 4 m

(nm

)

n (×10-3)

34

35

0 20 40 60 80 1000

100

200

300

400

500

PMMF

PSMF

× 4

Po

wer

(μ

W)

Current (mA)

0.0

0.3

0.6

0.9

1.2

1.5

1.8

Vo

ltag

e (V

)

1540 1545 1550 1555 1560 1565 1570 1575 1580 1585

-70

-60

-50

-40

-30

-20

Inte

nsi

ty (

dB

)

Wavelength (nm)

90 mA

85 90 95 100 105 110 115

0.24

0.28

0.32

0.36

0.40

Δλ

(nm

)

Current (mA)

-30

-20

-10

0

10

20

30

Intensity ratio

Inte

nsi

ty r

atio

(d

B)

current: 89 ~ 109 mA

Δλ: 0.25 ~ 0.39 nm

Δf: 30 ~ 48 GHz

注入窗口

FWM

a = 30 μm, w = 2.5 μm, current injection

region width W = 4 μm

Lasing characteristics of dual transverse modes

36

EDFA OBPFPD

ESA

DC bias

Schematic diagram for microwave generation based on the dual-mode microsquare laser

Microwave frequency of 30.56、32.70、35.12、39.51 GHz at current of 90, 95, 100, and 105 mA.

Opt. Lett. Vol. 40, p.3548(2015)

Tunable microwave based on the dual mode laser

1561 1562 1563 1564 1565 1566

-60

-30

0

30

60

90

120

105 mA

100 mA

95 mA

Inte

nsi

ty (

dB

)

Wavelength (nm)

90 mA

27 30 33 36 39 42-70

-65

-60

-55

-50

-45

-40

-35

-30

-25

105 mA100 mA95 mA90 mA

Inte

nsi

ty (

dB

)

Frequency (GHz)

a = 16 m ，w = 1.5 m， δ = 0, 0.5, 0.9, 1.3 μm

Deformed Sqaure resonator with high Q factor and enhanced transverse mode interval

37

THz wave generation based on deformed square microlasers

Corresponding to 0.43,

0.31and 0.16 THz

38

a = 16 m ，w = 1.5 m， δ = 0, 0.5, 0.9, 1.3 μm

报告提纲





39

40

互注入双圆微腔激光器

a) ICP刻蚀后的

SEM照片 b) 器件的显微镜

照片

a) PI曲线 b) 光谱

自由工作状态激光器A和B：

Appl. Phys. Lett. vol.106, 191107(2015)

41

Ia=29 mA


Ib=20 mA

42

张弛振荡峰高度：4.8 dB

张弛振荡频率：9.6 GHz

3dB带宽：14.65 GHz






0 20 40 60 800.0

0.5

1.0

1.5

2.0

2.5

3.0

L-I

L-I

Outp

ut pow

er

(mW

)

FP injection current (mA)

ISQ = 0

ISQ = 10 mA

SMF

287 K

V-I

0.5

1.0

1.5

2.0

Voltage(V

)

单模光纤耦合输出功率2.8 mW

正方形边长a = 15 μm；

FP腔宽度 d = 2 μm 长度 L= 300 μm

1520 1530 1540 1550 1560 1570

-70

-60

-50

-40

-30

fp: 1 mA

squ: 10 mA

Inte

nsity (

dB

m)

Wavelength (nm)

14.9 nm

-60

-40

-20

0

fp: 40 mA

squ: 10 mASMSR: 50 dB

SMSR: 27 dB

WG-FP耦合模：SMSR = 50 dB

正方形WG模：SMSR = 27 dB

FSR = 14.9 nm

高速单模定向输出WG-FP耦合微腔激光器

43

0

30

60

90

120

150

180

CC laser

In-plane远场发散角~30°

小信号直接电流调制FP腔：

光谱随FP腔注入电流变化(ISQ = 10 mA) 稳定单模工作，不跳模

光谱随square腔注入电流变化(IFP = 40 mA)

0 3 6 9 12 15 18-12

-6

0

6

13 GHzM

od

ula

tio

n R

esp

on

se

(d

B)


FP:25 mA

FP:40 mA

FP:55 mA

ISQ = 10 mA

13 GHz

高速单模定向输出WG-FP耦合微腔激光器

44

图3光谱图与FP腔电流关系，10~70mA单模激射没跳模，对应激射模波长红移3.3nm。由此推断温度上升33K。

0 20 40 60 80

0

1

2

3

4

5

Po

we

r (m

W)

Current(mA)

290K

287K

ISQ

= 10 mA

-60

-40

-20

0

1520 1525 1530 1535 1540 1545 1550 1555 1560 1565 1570 1575 1580

-70

-60

-50

-40

-30

Inte

nsity (

dB

m)

FP:50 mA

square:10 mA

(a)

FP:5 mA

square:10 mA

Inte

nsity (

dB

m)

Wavelength (nm)

(b)

图1. 单模光纤耦合功率与FP腔电流关系，正方形腔电流10

图2. 激光光谱正方形腔和FP腔电流(a)10mA和50mA，边模抑制比48dB；(b) 5mA和10mA.

另一激光器结果：

45

46

Documents

Whispering-Gallery Mode Microlasers