Wafer fusion is a powerful technique for fabricating
structures that cannot be realized by conventional epitaxial growth
and processing. Wafer fusion provides an extra degree of freedom
in the design and fabrication of 3-D photonic devices. Large
switch arrays can be produced by displacing the input and output
waveguides vertically in different planes. Compact
high-extinction-ratio directional couplers are essential to the
Using wafer fusion, scientists at the University of
California have fabricated a novel vertical-directional coupler
with a very short coupling length (47 micrometers).
The vertical coupler provides multilevel
capabilities of importance to the entire optoelectronics industry.
The new UC technology enables the development of
compact and scalable 3-D directional couplers (by allowing vertical
separation of input and output waveguides), and solves some of the
problems in optical switching.
B. Liu, A. Shakouri, P. Abraham, B. Kim, A. W.
Jackson, and J. E. Bowers, "Fused Vertical Couplers," Applied
Physics Letters 72(21): 2637-2638 (1998).
|United States Of America||Issued Patent||6,385,376||05/07/2002||1998-080|
optoelectronics, indoptoelec, indansens