Dynamic wavelength selective add/drop node comprising tunable gratings

H. Okayama; Y. Ozeki; T. Kunii

doi:10.1049/el:19970607

Dynamic wavelength selective add/drop node comprising tunable gratings

Electronics Letters ◽

10.1049/el:19970607 ◽

1997 ◽

Vol 33 (10) ◽

pp. 881 ◽

Cited By ~ 22

Author(s):

H. Okayama ◽

Y. Ozeki ◽

T. Kunii

Keyword(s):

Tunable Gratings

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Analog Piezoelectric-Driven Tunable Gratings With Nanometer Resolution

Journal of Microelectromechanical Systems ◽

10.1109/jmems.2004.839592 ◽

2004 ◽

Vol 13 (6) ◽

pp. 998-1005 ◽

Cited By ~ 35

Author(s):

C.W. Wong ◽

Y. Jeon ◽

G. Barbastathis ◽

S.-G. Kim

Keyword(s):

Nanometer Resolution ◽

Tunable Gratings

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Extending the Alvarez-Lens Concept to Arbitrary Optical Devices: Tunable Gratings, Lenses, and Spiral Phase Plates

IEEE Transactions on Terahertz Science and Technology ◽

10.1109/tthz.2017.2692042 ◽

2017 ◽

Vol 7 (3) ◽

pp. 320-325 ◽

Cited By ~ 9

Author(s):

Stefan F. Busch ◽

Jan C. Balzer ◽

George Bastian ◽

Graham E. Town ◽

Martin Koch

Keyword(s):

Optical Devices ◽

Phase Plates ◽

Tunable Gratings ◽

Spiral Phase

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Design, Dynamics and Active Control of Micro Interferometers for Low Noise Parallel Operation

Volume 13: Nano-Manufacturing Technology; and Micro and Nano Systems, Parts A and B ◽

10.1115/imece2008-69238 ◽

2008 ◽

Author(s):

Omkar Karhade ◽

Levent Degertekin ◽

Thomas Kurfess

Keyword(s):

Noise Reduction ◽

Range Of Motion ◽

Active Control ◽

Control Algorithm ◽

Cutoff Frequency ◽

Low Noise ◽

Experimental Results ◽

Ambient Vibration ◽

Limited Range Of Motion ◽

Tunable Gratings

Micromachined Scanning Grating Interferometer (μSGI) array offers a viable solution to the high resolution, large bandwidth, non-contact and high throughput metrology. Parallel active control of μSGIs is necessary to reduce the effect of positioning errors and ambient vibration noise. To achieve individual control of the μSGIs, the gratings in the μSGI are micromachined on Silicon membranes, which can be electrostatically actuated. These tunable gratings are designed to have sufficient range of motion (∼400nm) and sufficient bandwidth (∼50kHz) for effective noise reduction. The tunable gratings are fabricated successfully using Silicon on Insulator wafers with a two mask process. A novel recurrent calibration based control algorithm is designed to actively control the tunable gratings. The novel algorithm is implemented digitally using FPGA on an array of μSGIs simultaneously. The algorithm compensates for the non-linearities of the actuator and problem due to limited range of motion. A system model is built to design and analyze the control algorithm and is verified by experimental results. Experimental results show 100 times noise reduction at low frequencies and 6.5kHz noise reduction cutoff frequency. A resolution of 1×10−4 nmrms/√Hz is achieved by implementation of this algorithm on μSGI.

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