This PDF file contains the front matter associated with SPIE Proceedings Volume 6715, including the Title Page, Copyright information, Table of Contents, Introduction, and the Conference and Symposium Committee listings.

This paper presents the design, fabrication and operation principle of an optical beam steerer for laser fiber coupling based on a MEMS device. The MEMS chip consists on a bi-dimensional movable platform based on uni-dimensional comb drive actuation. An optical lens is assembled onto the mobile platform to focus and steer the light comping from a laser diode and couple it into an optical fiber. Assembly of a complete system and measurements were performed and compared to simulation results. Both the trajectory of the MEMS and resonance frewquency measurements agree with the simulated ones.

This work deals with the application of parallel robots for the correction of defocus and coma optical aberrations in the case study of the VST (VLT Survey Telescope) telescope, to be installed at the ESO observatory of Cerro Paranal (Chile). The parallel robots are used to change position and orientation of the secondary mirror. The secondary mirror positioning capability is a fundamental part in an active optics system, i.e. a closed loop control system for the minimization of the telescope optical aberrations, where the outer optical feedback coming from the wavefront sensor is used to generate references for the inner motion control loop of the secondary mirror positioning robots. Two devices are presented: a 6-6 Stewart platform where both fixed and mobile platforms are regular and similar hexagons whose vertexes belong to the same plane and are on a circle, and a two stages device composed by a XY table plus a tilt platform. The basic theory of active optics corrections is presented. The kinematics of both devices is solved in connection with the active optics application; first test data are presented.

We report on micromirror arrays being developed for object selection in Multi Object Spectrographs for astronomical applications. The micromirrors are etched in bulk single crystal silicon whereas the cantilever type suspension is realized by surface micromachining. One micromirror element is 100μm × 200μm in size. The micromirrors are actuated electrostatically by electrodes located on a second chip. The use of silicon on insulator (SOI) wafers for both mirror and electrode chip ensures thermal compatibility for cryogenic operation. A system of multiple landing beams has been developed, which passively locks the mirror at a well defined tilt angle when actuated. The mechanical tilt angle obtained is 20° at a pull-in voltage of 90V. Measurements with an optical profiler showed that the tilt angle of the actuated and locked mirror is stable with a precision of one arc minute over a range of 15V. This locking system makes the tilt angle merely independent from process variations across the wafer and thus provides uniform tilt angle over the whole array. The precision on tilt angle from mirror to mirror measured is one arc minute. The surface quality of the mirrors in actuated state is better than 10nm peak-to-valley and the local roughness is around 1nm RMS. Preliminary cryogenic tests showed that the micromirror device sustains 120K without any structural damage.

The ability to perform non-mechanical optical beam steering is of critical importance in laser communication and remote sensing; it is as vital as a phased-array antenna is for RADAR. This challenge has been addressed in the past primarily by liquid crystal (LC) devices. To date, a peak optical steering angle of ±4.53 degrees has been achieved, but it is limited by the fringing field effect. This limiting effect has been circumvented by depositing a thermo-optic material, polydimethlyoxane (PDMS), on a stair-step-approximated, blazed grating. The phase gradient can be controlled, while the material's index of refraction remains homogeneous throughout. The design, fabrication, simulation and performance of such a prototype, reflection-mode device is analyzed. Angular control between orders separated by 0.75 and 1.2° is experimentally demonstrated. An analysis of the efficiency and response time (2.2 μs) of the device is also presented. This approach promises circumvention of the fringing field effect, as well as much simpler and less-expensive fabrication.

The proposed passive thermal compensation mechanism is intended for maintaining the stability of performance parameters of an optomechatronic system over a wide operating temperature range. When integrated with airborne and military optomechatronic devices, this mechanism will also ensure their proper operation in harsh environments, characterized by exposure of the equipment to vibrations and shocks. Existing mechanisms designed for such purposes are only partially compliant. The proposed mechanism presents a simple structure consisting of two links and a frame. One end of each link is joined to the frame; the links are joined together at their other ends. All of the joints are hinged. At constant temperature, this structure has a zero degrees of freedom. One of the links is made from a material having a Coefficient of Thermal Expansion (CTE) different from that of the frame and the other link. When ambient temperature changes, the lengths of the links change in proportion to their respective CTE values. This results in one of the links performing a rotational motion. Exploitation of these phenomena allows the mechanism described herein to act as a motion amplifier. The amplifier Input is a small dimensional change in the links, caused by temperature change and its output is the rotational motion of The output link. The amplification is according to the rules of lever dynamics.

In this work, compact auto focus actuator moving lens module in the camera phone is developed by applying piezoelectric single crystal. This actuator is reduced in the size by applying the piezoelectric single crystal. The size of developed actuator (12*9.2*5.6 mm³) is reduced to 60.4% compared with the actuator using general voice coil motor. From the performance test, the developed actuator has moving stroke of 0.16mm, full stroke hysteresis of 5μm, settling time of 150msec, maximum overshoot of 7%, and unit step motion of 1μm. The manufacturing method for proposed actuator can be applicable to the nano-millimeter resolution and sub-millimeter stroke positioning system using for precision measuring microscope.

As one category of light-driven actuators, we propose a light-actuated device which outputs sound. To verify the feasibility of the concept of the light-actuated speaker, we performed experiments using a scheme where the light energy is first converted into an electrical current which then drives the connected speaker. The method seems rather indirect, but given the efficiency of the solar cell, which can reach around 25% with the use of an appropriate wavelength, and with the adoption of impedance matching between the solar cell and the speaker, a high overall conversion efficiency is expected. With its realization, it would be possible to create a sound system that is wireless and can be controlled remotely without the need of a power supply which will provide advantages over the conventional electronic transmission such as wireless operation with no external power source, and precise control of listening area compared to radio transmission. Possible applications include a sound guidance system for the visually impaired.

Micro Electro Mechanical Systems (MEMS) are among the new and emerging technologies of the future and have many applications in different disciplines. This study presents the dynamic characterization methods that we use to identify the modal parameters of a MEMS device and also the techniques that can be implemented to change the modal parameters. A micro scanner mirror was chosen as the case study to demonstrate the developed methodologies. Initially, the micro mirror was dynamically characterized using experimental modal analysis techniques to identify the modal parameters such as resonance frequencies and mode shapes. Then, it was introduced in a velocity feedback control loop to alter the effective damping of the structure. This method proves to be a very efficient method to alter the modal damping of a micro structure, especially when high quality factors are required for MEMS applications.

Mobile micro-robots are needed for micro positioning, manipulation or manufacturing small components, or sensing in chemical and biological environments. The design of mobile micro-robots poses challenges in terms of fabrication, actuation and sensing. Current approaches require complex assembly or sophisticated MEMS processes, to obtain actuators with a high energy density. Furthermore, the energy source for locomotion has either to be carried onboard (which by itself poses additional miniaturization challenges) or be remotely located so that the energy is transferred through tethered cables or wirelessly. In this paper, we propose a radically different approach: the micro-robot consists of a single piece of shape memory alloy (SMA) suitably shaped to perform inchworm-like locomotion, and remotely actuated by a laser beam. We report the modeling and design of an SMA inchworm like micro-robot, and the first experimental results.

In this paper, a cantilever-based manipulator using (1-x)Pb(Mg_1/3Nb_2/3)O₃-xPbTiO₃ (PMN-PT) single-crystal relaxor ferroelectric material is presented. We report the design of a novel piezoelectric multi-degree-of-freedom motion cantilever. The structure has interdigitated electrode (IDE) on the top and bottom surfaces of the cantilever and possesses both longitudinal and flexural actuation capabilities. PMN-PT materials are ideal for actuator applications since they exhibit a very high piezoelectric strain. We separately pattern interdigitated electrode (IDE) on the top and bottom surfaces of a single crystal cantilever beam. Furthermore, we propose a novel L-shaped cantilever manipulator that can provide up to four-degrees of freedom motion. The small and planar structure has potential applications in optical beam steering systems and nano-manipulators inside a scanning electron microscope.

Building on the technology developed to make deformable secondary mirrors for large telescopes, we show that a new breed of tip-tilt and low order deformable mirrors can be designed to satisfy the need of a large number of traditional astronomical AO systems that rely on a high order piezo deformable mirror compounded with a tip-tilt mirror to compensate for the large image motion present in the atmosphere. Using a new paradigm, we are developing a compact 50mm deformable mirror which benefits from a large computer power used to implement powerful control algorithms that allow speeding up the mirror response. Freed from the space and geometrical constraints that deformable secondary mirrors must respect, our mirror also displays elegant simplicity and compactness.

An optical driven actuator has a feature of a non-contact for applying light energy remotely. A laser trapping and a laser manipulation for small particles are powerful tool for nano-micro bio-technology. Nowadays, vectorial vortex attracts the attention of a laser trapping and a laser manipulation for small particles because it can rotate the particle by polarization. In this paper, a spatially variant polarized beam called vectorial vortex array is proposed. The mechanism of generation of the spatially variant polarized beam is examined the properties of polarization on beam profile. The generation mechanism of the beam consists of phenomena of the polarization and the interference. The vectorial vortex array is converted to different spatially variant polarized beams by adding a half wave plate. Their polarized beams are shown in experimentally.

Over the last several years, MEMS deformable mirror technology has evolved from a specialized wavefront control device used by only a few select research organizations to a low cost and high performance product that can now be considered for inclusion in certain commercial machines and instrumentation. In a typical MEMS deformable mirror, a membrane is suspended over a pattern of electrostatic actuators, with the possibility of additional microstructures to affect the membrane movement. Because the electrostatic actuators in the MEMS deformable mirrors can only pull on the membrane surface and because the shape of the membrane itself is determined by the associated membrane mechanics, there are limitations and tradeoffs in the achievable shape corrections. Our research seeks to clarify and define: (1) the actual wavefront correcting capabilities of the different MEMS deformable mirror designs and (2) how to effectively design optical systems to best utilize this new technology. After describing a finite element model of a three layer MEMS deformable mirror technology, a method for integrating high fidelity models of deformable mirrors with commercial optical design and simulation software is described. We then suggest a design methodology for both evaluating the performance of the deformable mirror and optimizing the optical system itself to best utilize the MEMS deformable mirror such that the static optical elements are tailored to the specific shape correcting capabilities of the deformable mirror. Simulated results are presented of a defocus case study with more than 7 waves of correction, with the final results analyzed.

High-speed, high-resolution, miniature photospectroscopy techniques suited for a microfluidic platform enable rapid, cost-effective and efficient assays for use in the clinic, or home, in the field with emergency medical personnel, or on biochemical production lines. We demonstrated an innovative MEMS tunable diffraction grating implemented for spectroscopic measurements requiring simple optics and signal processing. The device is composed of a polydimethylsiloxane (PDMS) microbridge with a nanoimprinted grating pattern on the top surface. MEMS silicon comb drive actuators mechanically strain the microbridge in order to variably tune the grating period. Our innovative nano photonic technology incorporating the tunable grating may guide future advancements of wavelength-discriminating detection for the identification and quantification of chemical and biological species.

In this paper a novel scheme for optical manipulation of objects utilizing the frequency difference of two separate lasers is proposed. In this scheme interference fringes moving at constant speed generated from two counter-propagating laser beams are expected to transport small particles trapped. For this purpose a highly stable light source is needed. On the other hand, actuators are nowadays widely used for controlling the position of or moving an object. Among them, piezoelectric actuators are commonly utilized to accurately control the angle of a diffraction grating in an external cavity laser diode (ECLD). However, conventional use of piezoelectric actuators in ECLDs causes difficulty in continuous scanning of the wavelength of an ECLD. Here, the 'tandem ECLD' utilizing an electromagnetically-driven actuator instead of a piezoelectric actuator is proposed based on the theoretical calculation that, when two separate lasers with different wavelengths sharing a common perturbation term are combined, the wavelength of the combined laser can be controlled in terms of the frequency difference of the two lasers. The wavelength shift of a prototype of the 'tandem ECLD' with respect to the current applied to the electromagnetically-driven actuator is measured. It is shown that the wavelength tuning method of an laser diode (LD) using an electromagnetically-driven actuator at low voltage exhibits equivalent performance (2.51nm wavelength shift when 2.58mA applied) to the conventional method that causes wavelength tunability using a piezoelectric actuator.

Optical waveguides used as a local light source along a fluidic channel have proven to be an effective approach to detecting cells in the field of flow-cytometry. One challenge, however, has been a simple integration of optical waveguides with the fluidic channel. We employ the use of femtosecond laser-writing process to pattern a waveguide in the bulk of a fused-silica glass substrate housing a fluidic channel. We demonstrate an in-situ scheme for detecting sub-millimeter components based on such a monolithically fabricated device. By illuminating the waveguide and collecting the light signal past the channel, we detect opaque and transparent components between 300 - 500 μm in size, as each moves along the channel. Both an opaque square chip and a transparent bead attentuate the signal by more than 95% primarily due to reflection and refraction respectively. The signature of a transparent bead additionally shows attenuated peaks which we attribute to normal incidence of light from the waveguide. The projected sizes of the parts are determined with less than 1% uncertainty. We conclude that the femtosecond laser produced waveguides in fused-silica glass are a viable option for the detection of certain kinds of sub-millimeter components. This approach holds the prospects of fabricating complex three-dimensional networks of waveguides monolithically.

New light-driven actuators based on films of polymer polyvinylidene fluoride are described. The actuators use the photomechanical bending of the polymer film caused by low power laser radiation. The photomechanical effect combines physical mechanisms, such as anisotropic thermal expansion, converse piezoelectric mechanism, photovoltaic and pyroelectric, while thermal expansion is dominant for slow motion. Mechanical vibrations of the strips of the photomechanical polymer were observed with periodic pulsed laser excitation. The resonance frequency is inversely proportional to the square of the length of the strip, in agreement with the theory. Resonance frequency measurements were used to determine the modulus of elasticity of the films, which was close to 3.0x10⁹ Pa. Three possible applications are a photonic switch, an adaptive mirror, and an auto-oscillator. The proposed actuators have a potential of being used as the components of future light-driven micro/nano systems.

In the present paper, two arm micromanipulator for handling and/or assembling of minute objects in a fixed view by use of a pantograph mechanism is proposed and its performance is discussed. The pantograph mechanism has three parallelogram in the mechanism. In case of the pantograph mechanism, when two input actuators of the pantograph mechanism has a linear motion, one of the output link of the mechanism has a motion with constant orientation. And when an input link of the mechanism has a circular motion and when the output link has an endeffector with same length of a radius of the circular motion, the top position of the endeffector does not move. Therefore, if we use the manipulator as cell treatment manipulator, the view of motion area of the top of the endeffector does not move, only the direction of the output link of the endeffector can change like a circular motion. This motion is very useful for treating cells, electric micro devices, etc. Then, first, the motion principle and the motion function of the mechanism are explained. Second, the performance of the manipulator and, especially, the positioning precision of the manipulator are discussed.

This paper describes the fabrication and, in particular, the assembly processes of a miniaturized micro-optical system, to be integrated on a hybrid flexible module, which hosts also electronics and microsensors. The whole module was conceived to be mass-produced in order to be distributed in skin-like structures for robotic tactile applications. Nevertheless, it is generally suitable for sensing applications where the flexibility and the thickness of the sensing network are primary requirements. The micro-optical system works as a part of an optoelectronic transducer where electric signals, generated by tactile MEMS sensors, are computed by a microcontroller that drives the micro-optical system. This consequently generates optical radiation, by means of integrated light emitting diodes (LEDs), to be coupled into optical fibers, which waveguide signals to a CMOS optical sensor. Micro-machining and micro-assembly processes of miniaturized components are critical steps in order to fabricate many of these modules according to the application requirements.

An optical driven actuator has a feature of a non-contact for applying light energy remotely. It consists of a neodymium magnet as a movement, a ferrite magnet, two blocks of graphite and temperature sensitive ferrite. The neodymium magnet is levitated by magnetic force between the neodymium and ferrite magnet. When laser is irradiated on temperature sensitive ferrite, a magnetic force decreases by photo-thermal effect. As a result, the movement can be controlled in three-dimensional area.