Optical waveguides – Integrated optical circuit
Reexamination Certificate
2001-02-02
2003-10-21
Healy, Brian (Department: 2874)
Optical waveguides
Integrated optical circuit
C385S031000, C385S033000, C385S035000, C385S092000, C385S093000, C385S129000, C385S130000, C385S131000, C385S052000, C438S026000, C438S027000, C438S028000, C438S029000, C438S031000, C359S248000, C359S298000, C359S319000, C359S698000
Reexamination Certificate
active
06636653
ABSTRACT:
TECHNICAL FILED OF THE INVENTION
The present invention relates to micro-electromechanical systems (MEMS) with integrated optical devices, in particular, to an assembly having micro-lenses integrated with MEMS actuators.
BACKGROUND OF THE INVENTION
Optical communication systems increasingly require the use of lightweight and low-cost optical devices or subsystems. A large number of such optical devices or subsystems including optical transmitters and receivers used in prior art suffer from mediocre performance. Such optical transmitters or receivers are generally devised using micro-fabrication technologies with semiconductor and conductive material layers. However, the drive towards unprecedented functionality in such optical communication systems requires the seamless integration of micro-electrical, optical and mechanical components. The success of micro-electromechanical systems (MEMS) technology and general trends toward miniaturization of the optical devices or subsystems could significantly benefit optical communication systems. MEMS technology can meet the need for integrated optical devices or subsystems by using suitable semiconductor, insulator, and conductive material for multilevel layered miniature structures and interconnects. The deployment of MEMS technology, in optical communication systems, could allow fabrication of inexpensive optical devices in a batch process. Consequently, MEMS technology is poised to make a significant impact in the field of optical communications.
Although MEMS based optical devices are generally a fraction of cost, size, and weight of typical optical communication systems, they are significantly important for ensuring performance, reliability and affordability of such systems. Despite seemingly obvious advantages of MEMS technology for optical communication, enhanced MEMS fabrication methods are desired for new systems functionality. Regardless of the fabrication process employed, generally MEMS fabrication processes encompass three key features including miniaturization, multiplicity, and microelectronics. A typical MEMS fabrication approach includes a variety of deposition and etching steps that could be based on both wet and dry procedures that selectively add or remove material from a wafer. Among other things, however, the challenge is to provide an ease of fabricating and integrating MEMS components with micro-optical components both in monolithic and/or hybrid forms. Integrated micro-opto-mechanical components for optical communication systems including fiber-optic switches and/or optical interconnects can usher an optical communication revolution providing high bandwidth and speed increasingly desired for most advanced communication applications. For example, applications could include high bandwidth interconnect for high performance computer systems, reconfigurable crossbar interconnect for high bandwidth applications, streerable optical communication systems, and all-optical fiber crossbar switch.
At present, in a variety of optical communication systems, micro-optics elements such as reflective micro-optics elements are combined with micro-electromechanical systems (MEMS) to provide MEMS integrated micro-optical communication devices. Typically, such MEMS integrated micro-optical communication devices comprising reflective micro-optical elements suffer from several shortcomings. For example, in a variety of optical communication applications, it is difficult to micro-position various micro-optical elements for precise alignment of light beams or optical signals. Although the precision with which the micro-optical elements must be positioned varies according to a particular application, the micro-optical elements must oftentimes be aligned to within several microns to several tenths of microns. Typical applications that require such micro positioning include optical interconnect systems, laser communications systems, and free space fiber optic switches. For example, in free space fiber optic switches, alignment of a light beam or an optical signal emitted from an optical fiber is desired. More specifically, the alignment of the light beam of an input optical fiber, with another optical element is needed to perform free space beam steering of the light beam traveling through the input optical fiber. By appropriately micro positioning a micro-optical element relative to the input optical fiber or a laser diode, the light beam or optical signal provided by the input optical fiber or laser diode can be coupled to a respective optical fiber or a detector.
Unfortunately, for such optical communication systems, MEMS integrated micro-optical communication devices of the prior art have been limited in their abilities and applications. Furthermore, it is difficult to fabricate MEMS integrated micro-optical communication devices, which provide the desired ability to micro-position micro-optical elements for steering a light beam or an optical signal.
One technique for optical communication includes forming reflective micro-optical elements, such as micro-mirrors. Such prior art micro-mirror based micro-optical communication devices typically require numerous components to construct and operate, and hence are generally less reliable. In addition, most micro-mirrors based micro-optical systems require a multi-segment folded optical path that increases the size of the system. Therefore, in micro-mirrors based micro-optical communication devices, micro-mirrors can typically not be mounted in close proximity to optical sources, leading to less power efficiency and less compactness and reduced transmission distances.
Moreover, typical actuation force generators employed to selectively modify positions of the micro-mirrors, either in a reference plane or a selected direction, may not rapidly traverse a desired range of displacements for the micro-mirrors. In the absence of such capabilities, the utility and applications of MEMS integrated micro-optical communication devices having reflective micro-optical elements integrated with MEMS are significantly limited.
Accordingly, there is a need for improved micro-electromechanical systems (MEMS) integrated micro-optical communication devices suitable for beam forming and steering to enable optical communication including, but not limited to, an optical transmission, switching, and/or rapid alignment.
SUMMARY OF THE INVENTION
The present invention generally provides integrated micro-electromechanical systems (MEMS) and methods of fabricating and operating the same. In an exemplary embodiment, an integrated optical apparatus includes a micro-electromechanical member and a substantially transmissive micro-optical element coupled to the micro-electromechanical member such as a MEMS structure. The integrated optical apparatus may further include an actuator for operating the substantially transmissive micro-optical element to manipulate an optical output from an optical source disposed proximal to the micro-electromechanical member. The optical source may be in a coaxial alignment with the substantially transmissive micro-optical element such as a micro-lens. The micro-electromechanical member may be coplanar to the micro-lens, which may collimate or focus the optical output to form a light beam. The micro-lens may steer the light beam in a first selected direction responsive to an actuator input applied to the actuator. The actuator may selectively position the micro-lens in response to an actuating force for steering the focussed light beam in the first selected direction to form a steered light beam. The actuating force could be an applied voltage bias and an actuating force profile may determine the first selected direction and a position of the micro-lens. The actuator could be a comb drive actuator generally formed on a substrate. Such a comb drive actuator may include one or more fixed combs and one or more movable combs. The one or more movable combs may be displaced in response to the actuating force and they may include a frame to fixedly hold the micro-lens.
The comb drive actuator may furt
Hilbert Claude
Hu Kai
Miracky Robert F.
Reed Jason D.
Fulbright & Jaworski LLP
Teravicta Technologies, Inc.
LandOfFree
Integrated optical micro-electromechanical systems and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Integrated optical micro-electromechanical systems and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Integrated optical micro-electromechanical systems and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3112095