Highly reflective optical coatings for high-power applications of micro scanning mirrors in the UV-VIS-NIR spectral region

Sandner, Thilo; Schmidt, Jochen; Schenk, Harald; Lakner, Hubert; Yang, Minghong; Gatto, Alexandre; Kaiser, Norbert; Braun, Stefan; Foltyn, Thomas; Leson, Andreas

doi:10.1117/12.644626

Cited by 6 publications

(10 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For a high reflectance ≥95% in NIR, we had to use Au for optical coating. To enable thermal compensation of the stresses induced by the bonding processes, we used a symmetric coating design [ 65 ], depositing identical Au coatings on the front- and backside of the mirror. A small static mirror deformation of ≤100 nm was achieved after the WLVP process.…”

Section: Discussionmentioning

confidence: 99%

Wafer-Level Vacuum-Packaged Translatory MEMS Actuator with Large Stroke for NIR-FT Spectrometers

et al. 2020

Self Cite

View full text Add to dashboard Cite

We present a wafer-level vacuum-packaged (WLVP) translatory micro-electro-mechanical system (MEMS) actuator developed for a compact near-infrared-Fourier transform spectrometer (NIR-FTS) with 800–2500 nm spectral bandwidth and signal-nose-ratio (SNR) > 1000 in the smaller bandwidth range (1200–2500 nm) for 1 s measuring time. Although monolithic, highly miniaturized MEMS NIR-FTSs exist today, we follow a classical optical FT instrumentation using a resonant MEMS mirror of 5 mm diameter with precise out-of-plane translatory oscillation for optical path-length modulation. Compared to highly miniaturized MEMS NIR-FTS, the present concept features higher optical throughput and resolution, as well as mechanical robustness and insensitivity to vibration and mechanical shock, compared to conventional FTS mirror drives. The large-stroke MEMS design uses a fully symmetrical four-pantograph suspension, avoiding problems with tilting and parasitic modes. Due to significant gas damping, a permanent vacuum of ≤3.21 Pa is required. Therefore, an MEMS design with WLVP optimization for the NIR spectral range with minimized static and dynamic mirror deformation of ≤100 nm was developed. For hermetic sealing, glass-frit bonding at elevated process temperatures of 430–440 °C was used to ensure compatibility with a qualified MEMS processes. Finally, a WLVP MEMS with a vacuum pressure of ≤0.15 Pa and Q ≥ 38,600 was realized, resulting in a stroke of 700 µm at 267 Hz for driving at 4 V in parametric resonance. The long-term stability of the 0.2 Pa interior vacuum was successfully tested using a Ne fine-leakage test and resulted in an estimated lifetime of >10 years. This meets the requirements of a compact NIR-FTS.

show abstract

Section: Discussionmentioning

confidence: 99%

Wafer-Level Vacuum-Packaged Translatory MEMS Actuator with Large Stroke for NIR-FT Spectrometers

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…The options include integrated piezo resistive sensors [17] for position detection, highly reflective coatings [18] and fabrication of gratings (see section 2.7).…”

Section: Fabrication Processmentioning

confidence: 99%

The high versatility of silicon based micro-optical modulators

Schenk

2009

SPIE Proceedings

Self Cite

View full text Add to dashboard Cite

"One product, one process": This MEMS law is true for micro-optical modulators, too and thus puts a high load on every product and technology development team. On the other hand the law expresses nothing but the high versatility of the underlying usually silicon based technology. A huge variety of applications where an electromagnetic wave experiences a spatial-temporal modulation makes use of this technology: High resolution as well as ultra-compact displays, optical switches in telecommunication as well as data storage devices, spectrometers e. g. for quality control, as well as adaptive optics and pattern generation to mention only a few. The applications completely differ with regard to the requirements in almost all aspects. The most important drivers to use silicon based micro-optical modulators are high accuracy, high bandwidth and high miniaturization. A continuous further development of the technology can be reported. Novel optical, mechanical and electrical working principles are investigated to meet future requirements. After a short overview of the most typical applications of silicon based micro-optical modulators the high versatility of this technology is detailed by means of selected devices and applications. Single 1D and 2D micro mirrors with diameters of up to 4 mm e. g. for projection, imaging and spectroscopy are as well presented and discussed as micro mirror arrays comprising up to 1 million analog deflectable mirrors for image generation and phase modulation in microlithography and adaptive optics

show abstract

“…Use of Micro Scanning Mirror Technology offers several advantages like high frequency scanning and extreme miniaturization of scanning systems. At Fraunhofer IPMS a qualified micro scanning mirror technology with high flexibility and several options including diffraction gratings [2], integrated position sensors [3] and highly reflective coatings [4] was developed. The process, offered by MEMS Technologies Dresden, is based on the use of BSOI wafers with a 75 µm thick SOI layer.…”

mentioning

confidence: 99%

“…With torsional suspension 1D scanners with or w/o high reflective coatings e.g. for barcode scanning or laser treadment [4] can be realized. By patterning of the mirror plate scanning gratings for spectroscopy can be fabricated [2].…”

mentioning

confidence: 99%