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Choo and Muller (UC-Berkeley), Hilton Head Workshop 2004
EEL6935 Advanced MEMS 2005 H. Xie 21
A. Jain and H. Xie, MEMS 2005
• Maximum displacement of 280 µm achieved
• Actuation Voltage: <10V
1.5 Microlens Examples -6
EEL6935 Advanced MEMS 2005 H. Xie 22
• Graded-Index (GRIN) Fiber
2. GRIN Microlenses
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2. GRIN Microlenses
•GRIN Rod Lenses or GRIN Fiber Lenses• SelfocTM
• Input angle may not equal to output angle which depends on the length.
• At half or full cycle, the input and output angles are the same, or focused
• At ¼ or ¾ cycle, the output light rays are parallel, or collimated
• Pitch: The fraction of a full sinusoidal cycle that light goes through before leaving the fiber. For example, a 0.25-pitch lens collimates the input light.
One cycle
EEL6935 Advanced MEMS 2005 H. Xie 24
•Planar GRIN Microlenses• PMLTM
2. GRIN Microlenses
• Ion-exchange process: Thermal or field-assisted (electromigration)
• Index change is proportional to the percentage of exchanged ions
• The concentration of exchanged ions changes gradually according to the diffusion process
• Thermal Ion-exchange process• Index change is proportional to the percentage of exchanged ions• The concentration of exchanged ions changes gradually according
to the diffusion process
EEL6935 Advanced MEMS 2005 H. Xie 25
3. Microprisms
Challenge:Linear slope with sharp edge
Fabrication Techniques:Deep synchrotron or proton lithographyAnalog lithographyReflow and Mass-transport techniques
Fabricated using analog lithography by E.B. Kley and F. Thoma