Next Article in Journal
Connection of the SUMO Microscopic Traffic Simulator and the Unity 3D Game Engine to Evaluate V2X Communication-Based Systems
Next Article in Special Issue
A Microscale Linear Phased-Array Ultrasonic Transducer Based on PZT Ceramics
Previous Article in Journal
Towards Efficient Implementation of an Octree for a Large 3D Point Cloud
Previous Article in Special Issue
Occupational Risk Prevention through Smartwatches: Precision and Uncertainty Effects of the Built-In Accelerometer
Open AccessArticle

Characterization of Tunable Micro-Lenses with a Versatile Optical Measuring System

1
Dipartimento di Ingegneria Industriale e dell’Informazione, Università degli Studi di Pavia, 27100 Pavia, Italy
2
STMicroelectronics, 20010 Cornaredo (Mi), Italy
*
Author to whom correspondence should be addressed.
Sensors 2018, 18(12), 4396; https://doi.org/10.3390/s18124396
Received: 14 November 2018 / Revised: 7 December 2018 / Accepted: 9 December 2018 / Published: 12 December 2018
(This article belongs to the Collection Modeling, Testing and Reliability Issues in MEMS Engineering)
In this work, we present the results of the opto–electro–mechanical characterization of tunable micro-lenses, Tlens®, performed with a single-spot optical measuring system. Tested devices are composed of a transparent soft polymer layer that is deposited on a supporting glass substrate and is covered by a glass membrane with a thin-film piezoelectric actuator on top. Near-infrared optical low-coherence reflectometry is exploited for both static and low-frequency dynamic analyses in the time domain. Optical thickness of the layers and of the overall structure, actuation efficiency, and hysteretic behavior of the piezo-actuator as a function of driving voltage are obtained by processing the back-reflected signal in different ways. The use of optical sources with relatively short coherence lengths allows performing interferometric measurements without spurious resonance effects due to multiple parallel interfaces, furthermore, selecting the plane/layer to be monitored. We finally report results of direct measurements of Tlens® optical power as a function of driving voltage, performed by redirecting a He-Ne laser beam on the lens and monitoring the focused spot at various distances with a digital camera. View Full-Text
Keywords: lenses; microelectromechanical devices; micro-optics; optical interferometry; optical metrology; optical polymers; optical signal detection; piezoelectric actuators; piezoelectric film; thin film lenses; microelectromechanical devices; micro-optics; optical interferometry; optical metrology; optical polymers; optical signal detection; piezoelectric actuators; piezoelectric film; thin film
Show Figures

Figure 1

MDPI and ACS Style

Merlo, S.; Crisà, E.; Giusti, D.; Ferrera, M.; Soldo, M. Characterization of Tunable Micro-Lenses with a Versatile Optical Measuring System. Sensors 2018, 18, 4396.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Search more from Scilit
 
Search
Back to TopTop