微光機電系統與應用技術微光機電系統與應用技術

(1)

台灣師範大學機電科技學系 -1-

微光機電系統與應用技術微光機電系統與應用技術

Optical MEMS Technology and its application Optical MEMS Technology and its application

楊啟榮博士

副教授

國立台灣師範大學機電科技學系

Department of Mechatronic Technology National Taiwan Normal University

Tel: 02-23583221 ext. 14 E-mail:ycr@cc.ntnu.edu.tw

台灣師範大學機電科技學系 C. R. Yang, NTNU MT

-2-

Outline Outline

z Optical MEMS Devices

z Requirement for optical characteristics

z Microactuators for optical applications

z Case study

(2)

Optical MEMS Devices Optical MEMS Devices

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(3)

MEMS Applications for 21

MEMS Applications for 21 ^st ^st Century Century

z Optical MEMS

z Bio-MEMS

z RF MEMS

Comparative scale of semiconductor sensors.

μ-mechanical resonator for Frequency band 1MHz~1GHz

-6-

MEMS

MEMS - - A New Enabling Technology A New Enabling Technology for Photonic Systems

for Photonic Systems

(4)

Optical MEMS Components Optical MEMS Components

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MEMS Micro Optical Bench MEMS Micro Optical Bench

M. C. Wu & H. Toshiyoshi, CNOM 8th Annual Affiliates Meeting

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Micro Optical Bench Micro Optical Bench

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R. S. Muller, Berkeley

Functional passive:

Mirror Engine:

Comb actuator

Transmission

Micro optical scanner

(6)

Functional passive:

Mirror

Engine:

Comb actuator

Transmitting mechanism:

Linkage, gear Sandia National Lab.

Micro optical scanner Micro optical scanner

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Answer : No more manual assembling

Built in micro actuators to make 3-D structures

Question : What is the most significant difference between conve Question : What is the most significant difference between conventional ntional machining and micromachining.

machining and micromachining.

(7)

Micro Elevated Self

Micro Elevated Self- -Assembling Assembling by Built

by Built- -in Actuators in Actuators

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H. Toshiyoshi

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Refraction Refraction

Fully assembled refractive micolens

300 μm

Ming C. Wu, UCLA

http://www.omminc.com/mems.html

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(9)

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2D Motion by Scratch

2D Motion by Scratch- -Drive Actuators Drive Actuators

(10)

Far Field Beam Profile (1.55 um) Far Field Beam Profile (1.55 um)

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Luke P. Lee, Berkley, 2002

http://www-biopoems.berkeley.edu/Project-first.php

Confocal

Confocal Microscope Microscope

(11)

Reflection Reflection

Electrostatic Combdrive-Actuated Micromirrors for Laser-Beam Scanning and Positioning

M. H. Kiang, et al., J. MEMS, 7, 27 (1998).

Vertical Scan Horizontal Scan

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H. Toshiyoshi, Hilton Head (2000), J. MEMS 10 (2001)

Electrostatically

Electrostatically Actuated MEMS 2D Optical Scanner Actuated MEMS 2D Optical Scanner

(12)

3D Optical Scanner by Single Crystal 3D Optical Scanner by Single Crystal Si Si

-24-

Free Space Integrated Optics Ming C. Wu, UCLA http://www.omminc.com/mems.html

Diffraction

(13)

Dynamic focusing microlens

http://www.omminc.com/mems.html M. Wu, et al., 1998

-26- Micrograting

(topside)

(a) Front side (b) back side of the grating

(14)

The Grating Light Valve uses reflection and diffraction to create dark and bright image areas.

Grating Light Valve

Grating Light Valve (GLV) (GLV) Reflection and Diffraction

http://www.siliconlight.com/htmlpgs/glvtechframes/glvmainframeset.html Moving ribbon

Fixed ribbon

Air gap Silicon Substrate

-28-

A simple color display can be built using a single light source, single GLV, and rotating RGB filter disk.

An even simpler color display can be built

with 3 LEDs (RGB) and a single GLV

(15)

2 Parallel

2 Parallel- -plate plate Fabry Fabry- -Perot etalon tuned by translation movement Perot etalon tuned by translation movement http://www.ee.ucla.edu/labs/laser/index.html

Interference Interference

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Lucent, 1998 MARS

MARS – – Mechanical M echanical A Anti nti- -R Reflection eflection S Switch witch

Fully fabricated MARS device Si

Al

Ti/Au SiN

_x

Signal

Unbiased mλ/4 air gap (m odd -reflection)

Biased (m-1)λ/4 air gap (m even – anti-reflection)

(16)

Optical MEMS Applications Optical MEMS Applications

Micro

Micro- -optical bench optical bench

http://www.ee.ucla.edu/labs/laser/index.html z

Projection displays

z

Fiber switches

z

Filters and dispersion compensators

z

Optical scanners

z

Adaptive Optics

z

Silicon Optical Bench

z

Sensors with optical readout

z

Interferometers

z

Spectrometers

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Application of Optical MEMS Application of Optical MEMS

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Integrated Free

Integrated Free -Space Optical Disk Pickup Head - Space Optical Disk Pickup Head

http://www.ee.ucla.edu/labs/laser/index.html

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Digital Mirror Display/Digital Light Processing Digital Mirror Display/Digital Light Processing

Texas Instruments

15 μm

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光通訊系統傳輸容量的進展光通訊系統傳輸容量的進展

l

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訊號供應者

訊號接受者

微光學透鏡

旁路開關多工傳輸器

接續器

陣列開關多光纖連接器

分光器多工傳輸解譯器

光通訊系統架構示意圖

(19)

http://www.omminc.com/mems.html

Dynamic focusing microlens Deformable micro mirror

2 X 2 FDDI optical switch

Free Space Integrated Optics Rotating micro mirror

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輸入輸出

分波解多工器分波多工器

(a)光訊號作加成/消減(add/drop)示意圖；(b) OXC的架構示意圖

H. Toshiyoshi, Optical MEMS, UCLA, (2002).

(20)

DWDM基本原理如彩虹，多顏色合併後經光纖傳輸後分開波段

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Large Scale Optical

Large Scale Optical Crossconnector Crossconnector (OXC) (OXC)

• E. L. Goldstein, J. A. Nagel, J. L .Strand, R. W. Tkach, "Multiwavelength opaque optical-crossconnect network," Lightwave, Feb. 1998.

• M. C. Wu & H. Toshiyoshi, CNOM 8th Annual Affiliates Meeting

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Scanning Mirrors for OXC Scanning Mirrors for OXC

OXC: Optical Cross Connector OXC: Optical Cross Connector

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MEMS in WDM Network MEMS in WDM Network

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台灣師範大學機電科技學系 -43- 未施加電壓

液晶分子

施加電壓

液晶分子

液晶式光開關液晶式光開關

Spectraswitch Spectraswitch

液晶式光開關系統原理

液晶光開關圖例

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氣泡式光開關氣泡式光開關

Agilent

Horizontal section of the planar lightwave circuit (PLC). Multiple optical paths consist of intersecting waveguides created into the PLC.

A trench is etched at each crosspoint of the waveguides.

Then the trench is filled with a fluid having the same optical properties.

When the optical signal needs to be redirected the fluid is heated up and a bubble is generated.

(23)

As a default condition, the fluid enables the transmission of the light through the waveguide without changing it or deviating it.

When the fluid is heated up the bubble created reflects the light by total internal reflection providing a fast switching function. The optical signal transmitted is deviated but not deteriorated.

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全像術式光開關

全像術式光開關, Trellis Photonics

, Trellis Photonics

Singal input

Thermo-Optic

Phase Shifter 1st SW 2nd SW

Output Off State

Output On State

熱光式光開關熱光式光開關, NTT

, NTT

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聲光式光開關聲光式光開關

光源

聲波產生器

聲波轉折器

http://www.lmgr.net/aotechnology.htm

Acousto

Acousto- -Optic (AO) Technology Optic (AO) Technology

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各種光開關特性之比較

(25)

Requirement for optical characteristics Requirement for optical characteristics

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Reflectivity of Metals

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Coupling Distance of Fibers Coupling Distance of Fibers

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Collimated Beam Filter (Ball Lens)

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Source of the Insertion Loss Source of the Insertion Loss

Stability of Mirror Angle Stability of Mirror Angle

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光開關損失之原因

(28)

Fiber Coupling Fiber Coupling

G- G -FF Fiber: Fluoride glass Fiber, Multimode, KDD FF Fiber: Fluoride glass Fiber, Multimode, KDD TEC Fiber: Thermally Expanded Core Fiber TEC Fiber: Thermally Expanded Core Fiber

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Preparing

Preparing Photoresist Photoresist Reflow Reflow Lens Pattern Lens Pattern

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Lens Profile Model Lens Profile Model

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Photoresist

Photoresist Reflow Reflow Lens Lens

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Lens Shape (Sag) After

Lens Shape (Sag) After Photoresist Photoresist Reflow Reflow as a function of initial resist thickness as a function of initial resist thickness

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Lens Design 1 Lens Design 1

Initial Thickness

Initial Thickness -- --> Sag > Sag -- --> Radius of Curvature > Radius of Curvature -- --> Focal Length > Focal Length

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Lens Design 2 Lens Design 2

Beam Diameter and Lens Diameter

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Lens Design 3 Lens Design 3

Minimum Initial Resist Thickness

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Lens Design 4 Lens Design 4

Minimum Resist Thickness and Lens Diameter

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Transferring

Transferring Photoresist Photoresist Pattern into Silicon Pattern into Silicon

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Silicon Micro Lens Silicon Micro Lens

Shape Transferred by RIE Shape Transferred by RIE

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Effect of

Effect of Photoresist Photoresist Thickness Thickness

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Focal Length Simulation Focal Length Simulation

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Beam Spot Diameter

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Lens Diameter and Beam Spot Diameter Lens Diameter and Beam Spot Diameter

-70-

光熱能

Photothermal

水滴式

Droplet

折射式微透鏡

Refractive Microlens

灰階光罩

Gray Tone Mask

熱回流

Thermal Reflow

準分子雷射微加工

Excimer Laser Micromachining

直寫式

Direct Writing

離子交換

Ion Exchange

折射式微透鏡陣列製造技術

(36)

台灣師範大學機電科技學系 -71- A B C D E F

A: Fresnel 波帶片 B: 平面化二元式Fresnel微透鏡 C: 兩階二元式Fresnel微透鏡 D: 四階二元式Fresnel微透鏡 E: 鋸齒狀Fresnel微透鏡 F: 傳統透鏡

不同之Fresnel不同之

Fresnel透鏡與傳統透鏡之比較圖

透鏡與傳統透鏡之比較圖

-72- Mask

Crystal Substrate

RIE Crystal

Substrate HMDS Coating

Lithography Crystal

Substrate PR Coating

PR Crystal Substrate

Crystal Substrate Two-Step

Microlens HMDS & PR

Coating

RIE

Lithography

four-Step Microlens

微透鏡之半導體製作流程示意圖

(37)

Rochester Photonics Corp.

-74-

Delay Masking Process for

Delay Masking Process for Multistep Multistep Structures Structures

Makoto Mita, et al., HARMST'99, JAPAN.

(38)

Excimer

Excimer Laser Laser Micromachining: Mask Dragging Micromachining: Mask Dragging

shaped mask

SU-8光阻微透鏡陣列

光強度分布圖

氦氖雷射 CCD

物鏡

物鏡折射式微透鏡

陣列針孔

透鏡光圈

三維移動平台

光束品質分析器

光學檢測設備架構圖

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http://www.exitech.co.uk/

(39)

Mask

Workpiece Stage

Fresnel Lens

以以Mask Dragging

Mask Dragging 的方式製作微鏡片

的方式製作微鏡片

(b) Groove pattern of the kinoform cylindrical lens (a) Mask used to make cylinderical lens

Dark: 透光 Clear:不透光

-78-

準分子雷射單光罩多層階加工技術準分子雷射單光罩多層階加工技術

光罩圖案

雷射聚焦成像

加工圖案重疊

（光罩移動）

（工件固定）

光罩圖案

1 2 3

2 1

2 3

3 3

3

八階光罩組合

準分子雷射微透鏡加工技術

(40)

準分子雷射微加工準分子雷射微加工

微光學繞射元件製作與檢測

微光學元件檢測系統

像素5 μm四階全像片 “HELLO” 影像輸出

焦平面光強度十六階微透鏡陣列

孔徑250 μm、焦距15 mm

表面檢測光學檢測 準分子雷射LIGA製程

-80-

SU- SU -8 8光阻點膠滴置微透鏡陣列製作技術

光阻點膠滴置微透鏡陣列製作技術

微透鏡陣列活塞

針筒

玻璃基板 X

Y Z 定位平台

基座

控制器接高壓

氣體管路氣體源軟烤

UV曝光

曝光後烘烤

微透鏡點膠滴置架構

點膠滴置微透鏡製作技術

(41)

凹面型微光柵元件凹面型微光柵元件

-82-

Principle of the VIS

Principle of the VIS- -Spectrometer Spectrometer

Source: http://www.microparts.de/01OPTICVIS.htm Light input λ1….λx

through optical fiber

Light output via

45

^o

reflecting edge Diode array

Self focusing reflection grating (d=0.2 μm, g=2 μ m)

λ2λ1

Characteristics

z

Molded construction allows for cost effective volume pricing

z

Small dimensions, lightweight

z

Excellent thermal stability

z

Long-term stability

z

Flexible operation

z

Robust monolithic construction

z

No moving parts

(42)

台灣師範大學機電科技學系 -83- zGrating resolution : 7nm

zSpectral range: 380nm~780nm

zspectral resolution: 7nm (measured at 450 nm)

zDimension：10 × 10 × 5 cm

VIS-Microspectrometer PIDC-2000

國科會精儀中心

-84-

Microactuators

Microactuators for optical applications for optical applications

(43)

Actuator is Energy Converter Actuator is Energy Converter

-86-

Microactuators

Microactuators for Optical MEMS for Optical MEMS

(44)

Size reduction by MEMS technology Size reduction by MEMS technology

-88-

1984 1988

1989

1992

1993 1995

1997 1998 Comb-drive

W. Tang, et al.

Barcode scanner K. Y. Lau, et al.

MUMPs MCNC

Poly-Si beam R. T. Howe.

Micromotor Fan. Tai

Microhinge K. Pister

FS-MOB M. Wu

Raster-scanning MEMS display Fabrication platform

To use planar fabrication platform to make/integrate movable

components on substrate

(45)

What is expected out of MEMS for Optical Switch?

-90-

MEMS Optical Switches MEMS Optical Switches

(46)

1x4 1x4 光纖定位光開關

光纖定位光開關

光源輸入光纖

光源輸出光纖雙向定位光纖耦合

M. C. Wu, UCLA

Principles of Micro

Principles of Micro- -Optical Switch Optical Switch

2x2 微鏡面光開關 2x2

微鏡面光開關

-92-

不同埠數之光開關示意圖

(47)

MEMS Optical Switches MEMS Optical Switches

-94-

Digital Matrix Optical Switch on a Chip Digital Matrix Optical Switch on a Chip

zToshiyoshi and Fujita, “Electrostatic micro torsion mirrors for an optical switch matrix,” J. MEMS, vol.5, p.231-7, 1996.

zLin, Goldstein, Tkach, “Free-space micromachined optical switches for optical networking. IEEE JSTQE, vol.5, p.4-9, 1999.

zM. C. Wu & H. Toshiyoshi, CNOM 8th Annual Affiliates Meeting

(48)

-96- M. Hoffmann et al., JMM 9 (1999) 151

(49)

Switching cycle of a thermo-mechanical 1x2 moving-fiber switch

1 x 4 switch with coupled U-shaped actuator for large deflections

Photographs of a 1 x 4 switch

-98-

微反射鏡基本運動型式微反射鏡基本運動型式

(a) (b) (c)

(d) (e) (f)

(50)

by Built

by Built- -in Actuators in Actuators

-100-

Schematic of the fabrication process for surface-micromachinined microhinges.

Surface Micromachining for

Surface Micromachining for Hinged structures Hinged structures

M. C. Wu, et al., Sensors and Actuators A, 50(1-2), 127 (1995).

http://www.coventor.com/media/papers/optical_SOI.pdf

(51)

Polysilicon

Polysilicon Hinge Structure Hinge Structure

K. S. J. Pister, M. W. Judy, S. R. Burgett, R. S. Fearing,

"Microfabricated hinges," Sensors & Actuators A33, 1992

-102-

Bell-Lab./ Lucent M. C. Wu, UCLA

M. C. Wu, UCLA

Mirror

Mirror- -typed Optical Switch typed Optical Switch

R. S. Muller, Berkeley

(52)

16 x 16 array Switch http://www.omminc.com/home.html

Mirror

Mirror- -typed 2D Optical Switch typed 2D Optical Switch

M. C. Wu, UCLA

-104-

(53)

Large Scale MEMS Optical Switches Large Scale MEMS Optical Switches

-106-

3D Optical Switch

(54)

Mirror

Mirror- -typed 3D Optical Switch typed 3D Optical Switch

Bell-Lab./ Lucent

-108-

http://www.omminc.com/home.html

Mirror

Mirror- -typed 3D Optical Switch typed 3D Optical Switch

(55)

Scalability Scalability

-110-

MICRO MIRROR SWITCH MICRO MIRROR SWITCH

Redirection of light beams by electrostatic torsion mirrors Redirection of light beams by electrostatic torsion mirrors

Where is actuator ? Where is actuator ?

H.Toshiyoshi, H. Fujita, IEEE J. MEMS 5(4), 1996.

H.Toshiyoshi, H. Fujita, IEEE/LEOS 96, Colorado.

D. Miyauchi, H.Toshiyoshi, H. Fujita, IEEE/LEOS MOEMS 97, Nara.

(56)

Electrostatic Torsion Mirror Matrix Electrostatic Torsion Mirror Matrix

-112-

Optical Switching

(57)

Electrostatic Torsion Mirror Matrix Electrostatic Torsion Mirror Matrix

-114-

Problems of Prototype

(58)

Torsion Mirror Electrostatic Operation Torsion Mirror Electrostatic Operation

-116-

Operation Voltage

(59)

Fabrication Process Fabrication Process

-118-

Bulk & Surface

Bulk & Surface Micromachinings Micromachinings

(60)

Electromagnetic Torsion Mirror Electromagnetic Torsion Mirror

-120-

Electrostatic vs. Electromagnetic

(61)

Electromagnetic Latching Electromagnetic Latching

No power consumption to hold mirror No power consumption to hold mirror

-122-

Cross Connector by Electromagnetic Torsion Mirror

(62)

UCLA's First Generation Switch UCLA's First Generation Switch

S. S. Lee, E. Motamedi, and M. C. Wu, 1997 Transducers Paper 1A4.07P, 1997.

-124-

Electrostatic

Electrostatic S Scratch cratch -D - Drive rive A Actuator ctuator

Akiyama et al., IEEE J-MEMS, 1993, 1997

(63)

-126-

Automatic Self

Automatic Self- -Assembly by Curled Assembly by Curled- -up up Cantilever + Latch

Cantilever + Latch

H. Nguyen, R. Chen, M. C. Wu, UCLA, OSA-99

(64)

nm

R. Chen, H. Nguyen, M.C. Wu, IEEE MEMS Conference, 1999.

Curled Cantilever Switch Curled Cantilever Switch

-128-

2D Array of Curled Cantilever Switch

(65)

Bulk micromachined actuators for N x N cross-connects.

Cross section of a wet-etched comb drive.

-130-

Spherical lens

fiber fiber

Source: A. Müller et al., J. Micromech. Microeng., 3 (1993) 158-160

Single-mode fibres adjusted to a ball lens Schematic of a microoptical switch with

single-mode fibres

Movable mirror and fibre grooves mirror

LIGA Process for Optical Switch

(66)

Optical bench for alignment of fibers, lens and lasers Optical bench for alignment of fibers, lens and lasers

-132-

Micro-optical bench on top of a micromachined Si wafer

Scheme of concept to fabricate optical bench by LIGA process

(67)

應用X應用

X- -ray LIGA ray LIGA製程開發之光學陣列開關

製程開發之光學陣列開關

J. Mohr, A. Last, and U. Wallrabe, 8th Microoptics Conference, Osaka, Japan, (2001).

-134-

(68)

Grating Light Valve (GLV) Grating Light Valve (GLV)

-136-

GLV:1

GLV:1- -D Array type light valve D Array type light valve

(69)

The Grating Light Valve uses reflection and diffraction to create dark and bright image areas.

Grating Light Valve

Grating Light Valve (GLV) (GLV) Reflection and Diffraction

http://www.siliconlight.com/htmlpgs/glvtechframes/glvmainframeset.html Moving ribbon

Fixed ribbon

Air gap Silicon Substrate

-138-

(70)

-140-

(71)

A simple color display can be built using a single light source, single GLV, and rotating RGB filter disk.

An even simpler color display can be built with 3 LEDs (RGB) and a single GLV

-142-

Typical gain equalizer module requiring multiple VOA devices, one per channel

(72)

An HDTV – resolution projector utilizing three GLV device optical attenuator modules A three GLV color display solution is

shown for a large-screen projector.

-144-

微光機電系統與應用技術 微 光機電系統與應用技術