Integrated bi-directional focusing and tracking actuators in a monolithic device for a MEMS optical pick-up head

Abstract

This work presents a miniaturized two-degree-of-freedom (2-DOF) optical pick-up head implemented using MEMS technology. This device contains novel bi-directional vertical comb-drive actuators to act as the focusing positioner, and V-beam thermal actuators to serve as the tracking positioner. In addition, a UV-cured polymer droplet is used for an objective lens. Particularly, the focusing and tracking actuators are monolithically fabricated and integrated in a single device. Electrical routing and isolation is also available by poly-Si and Si3N4 multi-layers for 2-DOF operation. In applications, the proposed device has been successfully fabricated and characterized. The upward and downward displacements of the focusing optical pick-up head are 4.6 µm and 4.1 µm, respectively, at a 30 V driving voltage. And the in-plane displacement of the tracking optical pick-up head is ±16.3 µm, at a 5 V driving voltage. The resonant frequencies of the focusing and tacking systems are 1.9 kHz and 4.1 kHz, respectively.

Lens integrated with self-aligned variable aperture using pneumatic actuation method

“…lenses) can be greatly reduced [3,4]. Tunable mechanisms, such as XY-stages, have also been fabricated with silicon micromachining technology and successfully integrated with microlenses [5]. Although there has been obvious improvement in miniaturization of optical and supporting components, specially designed assembly structures and methods are still frequently required to achieve high-precision alignment of components.…”

Design and Characterization of Single-Layer Step-Bridge Structure for Out-of-Plane Thermal Actuator

“…The electrothermal actuators have the following advantages: low driving voltage, large output force, and large output displacement [1]- [4]. The existing reports also show the following advantages: simple fabrication process and easy integration with other microelectromechanical systems (MEMS) components for some electrothermal actuators [5], [6]. In applications, the electrothermal actuators have been applied to drive various MEMS devices [7]- [9].…”

Integrated Tracking and Focusing Systems of MEMS Optical Pickup Head

“…Several researches successfully used microelectromechanical systems (MEMS) technology to develop optical storage components [1]- [4]. However, it is a challenge to achieve a large stroke for a miniaturized device, especially in the out-of-plane direction.…”