Transcript
Datasheet: ML-15-35 Manual Focus Tunable Lens Update: 31.10.2008
Copyright © 2008 Optotune. All rights reserved.
Manual Focus Tunable Lens ML-15-35
This document summarizes the main characteristics of Optotune’s manual focus tunable lens. The shape of the lens can be changed from convex to concave and vice versa by simply rotating the outer ring attached to the lens. Depending on customer requirements, the lens aperture and thickness can be varied from sub-millimeters to several centimeters. Furthermore, the tuning range can be adjusted according to customer needs. The following table gives a technical overview over our standard sized, manual lens.
Test Conditions Lens diameter used for characterization Wavefront / PSF / MTF measured @ Coordinate system Focal length used for wavefront measurements Temperature
50 % of clear aperture 633 nm x = horizontal, y = vertical 130 mm 20° C
Mechanical Characteristics External Diameter Height Clear Aperture Recommended Aperture
Unit mm mm mm mm
Min. 34.95 9.95 14.95 -
Typical 35 10 15 8.6
Max. 35.05 10.05 15.05 -
Unit mm nm % λ λ λ mrad contrast
Min. -20 380 0.5 2 -
Typical infinity > 90 %(Vis) Figure 4 0.65 3 Figure 5 Figure 7
Max. +20 1000 1.5 5 -
Unit °C °C
Min. -40 -20
Typical +20 +20
Max. +100 +85
Optical Characteristics Focal Tuning Range Wavelength Range Transmission @ 532 nm Spherical aberrations Wavefront RMS Error @ 633 nm Wavefront Peak Value (PV) Error Point Spread Function (PSF) Modulation Transfer Function (MTF)
Thermal Characteristics Storing Temperature1 Operating Temperature1
1
Estimate (tested for each component separately) Page 1 of 7 No representation or warranty, either expressed or implied, is made as to the reliability, completeness or accuracy of this paper. Ueberlandstrasse 129 | CH-8600 Dübendorf | Switzerland Phone +41 44 823 43 25 | www.optotune.com |
[email protected]
Datasheet: ML-15-35 Manual Focus Tunable Lens Update: 31.10.2008
Copyright © 2008 Optotune. All rights reserved.
Figure 1 shows the dimensions of the ML-15-35 lens. As can be seen in the diagram, the focal ranges given in the table above are measured starting from the cover glass. The gray ring is used to set the focal range to the desired value.
10
35
15
aperture
focal length
2.2 Figure 1: Technical diagram (unit: mm)
The transmission spectrum between 350 nm and 1000 nm can be seen in Figure 2.
Figure 2: ML-15-35 transmission spectrum
Page 2 of 7 No representation or warranty, either expressed or implied, is made as to the reliability, completeness or accuracy of this paper. Ueberlandstrasse 129 | CH-8600 Dübendorf | Switzerland Phone +41 44 823 43 25 | www.optotune.com |
[email protected]
Datasheet: ML-15-35 Manual Focus Tunable Lens Update: 31.10.2008
Copyright © 2008 Optotune. All rights reserved.
The shape of the ML-15-35 lens is best approximated by Hencky’s formula. A comparison of Optotune’s lens to an ideal lens as well as the recommended aperture (3.6mm) area shown in Figure 3.
Figure 3: Lens shape comparison
The Hencky approximation is given by: 𝐻 𝑟, 𝑎, 𝑤0 = 𝑤0 1 − 0.899
𝑟2 𝑟4 − 0.101 4 2 𝑎 𝑎
Where 𝑎 is the radius of the lens aperture, 𝑤0 is the center deflection and 𝑟 is the radius at the current position of 𝐻(𝑟, 𝑎, 𝑤0 ). For a our lens, the center deflection 𝑤0 (at no applied voltage) amounts to 610 𝜇𝑚.
Page 3 of 7 No representation or warranty, either expressed or implied, is made as to the reliability, completeness or accuracy of this paper. Ueberlandstrasse 129 | CH-8600 Dübendorf | Switzerland Phone +41 44 823 43 25 | www.optotune.com |
[email protected]
Datasheet: ML-15-35 Manual Focus Tunable Lens Update: 31.10.2008
Copyright © 2008 Optotune. All rights reserved.
Figure 4 shows the wavefront error measured using a Shack-Hartmann sensor. The observed coma in ydirection is the so-called gravity-effect which can be lowered by employing the lens in a plane perpendicular to gravity. This effect is strongest for short focal lengths.
Figure 4: Wavefront error
Page 4 of 7 No representation or warranty, either expressed or implied, is made as to the reliability, completeness or accuracy of this paper. Ueberlandstrasse 129 | CH-8600 Dübendorf | Switzerland Phone +41 44 823 43 25 | www.optotune.com |
[email protected]
Datasheet: ML-15-35 Manual Focus Tunable Lens Update: 31.10.2008
Copyright © 2008 Optotune. All rights reserved.
Figure 5 shows the Point Spread Function. Artifacts in y-direction are caused by the gravity-effect described above.
Figure 5: Point Spread Function
Figure 6 shows a x- and y-cut of the Point Spread Function through the center of Figure 5.
Figure 6: X- and Y-cut of the Point Spread Function
The Modulation Transfer Function calculated from the wavefront error for both the x- and y-axis can be seen in Figure 7.
Page 5 of 7 No representation or warranty, either expressed or implied, is made as to the reliability, completeness or accuracy of this paper. Ueberlandstrasse 129 | CH-8600 Dübendorf | Switzerland Phone +41 44 823 43 25 | www.optotune.com |
[email protected]
Datasheet: ML-15-35 Manual Focus Tunable Lens Update: 31.10.2008
Copyright © 2008 Optotune. All rights reserved.
Figure 7: Modulation Transfer Function
Page 6 of 7 No representation or warranty, either expressed or implied, is made as to the reliability, completeness or accuracy of this paper. Ueberlandstrasse 129 | CH-8600 Dübendorf | Switzerland Phone +41 44 823 43 25 | www.optotune.com |
[email protected]
Datasheet: ML-15-35 Manual Focus Tunable Lens Update: 31.10.2008
Copyright © 2008 Optotune. All rights reserved.
Figure 8 shows a common test image featuring some small patterns and gradients. Figure 9 is the image observed after the lens. One can clearly see some blurring mainly caused by the coma seen in Figure 4. However, for imaging systems, this error can be reduced by software.
Figure 8: Unprocessed test image
Figure 9: Processed test image
Page 7 of 7 No representation or warranty, either expressed or implied, is made as to the reliability, completeness or accuracy of this paper. Ueberlandstrasse 129 | CH-8600 Dübendorf | Switzerland Phone +41 44 823 43 25 | www.optotune.com |
[email protected]
