EL-6-18

Focus Tunable Lenses

Optotune is a leading supplier of focus tunable lenses for diverse applications. Whether electrically or mechanically actuated, the advantages of tunable lenses over traditional optics are striking. Optotune's lenses can be taylored to your specific demands in terms of size, tuning range, transmission range or speed. Tell us your requirements and we will be happy to assess the feasibility.

Advantages
A change in lens radius of several micrometers can have the same optical effect as moving the entire lens several centimeters. Optical systems can be designed more compact, oftentimes with less lenses and usually with less or no translational movement. Accordingly, there is no more need for expensive mechanical actuators. Less movement also leads to a more robust design, which can be completely closed so that no dust can enter. Furthermore, the materials employed are lighter than glass, saving overall weight. Less movement and weight also means less power consumption and that the response time of systems with tunable lenses can be very low, in the order of milliseconds. Another advantage becomes obvious during production. The fact that less optical parts are moved combined with the tunability of the radius during operation results in reduced tolerance sensitivity and thus higher yield rates.

To summarize, these are the five main advantages of focus tunable lenses over traditional optics:
● Compact design
● Less mechanics
● Fast response
● Low power
● Less tolerance sensitivity
  • 型號
  • 產品概述
  • 庫存
  • 詢價數量
  • 詢價車
EL-6-18

Electrical type, C.A. 6mm

  • Mechanical specifications

     Dimensions (L x W x H)  18 x 19.3 x 8.7 mm
     Clear aperture  6 mm
     Weight  6.7 g
     Lifecycles (10-90% sinusoidal)  >1‘000‘000’000
     Vibration resistance  IEC 60068-2-6: 10G (10-50 Hz) in operation
     Drop test  50 drops from 2 m

    Electrical specifications

     Resistance (@ 20°C)  8.8 +/- 0.4 Ω
     Control current (typical)  0 to 200 mA
     Power consumption  0 to 350 mW
     Response time (10%-90% step)  <2 ms
     Settling time  <10 ms
     Electrical connectiont  6 way 0.5mm pitch
     Integrated temperature sensor / memory  STTS2002

    Optical specifications

     Focal tuning range at STP  -500 to +50 mm (-2 to 20 dpt)
     Wavelength range  400 to 700 nm
     Dispersion (at 20°C)  nF (486.1nm) 1.302
     nD (589.3nm) 1.300
     nC (656.3nm) 1.299
     Abbe number Vd 100
     Lens type  Meniscus (concave-convex)
     Full field of view  40°
     Polarization  Preserving

    Thermal specifications

     Operating temperature  -20 to +70°C
     Storage temperature  -40 to +85°C

    Regulatory Requirements

     Materials  Complies with EU directive 2002/95/EC (RoHS)

     

加入
EL-10-30-HR

Electrical type, High refraction, C.A. 10mm

  •  Clear aperture  10 mm
     External diameter  30 mm
     Thickness  10.7 mm
     Weight  22.6 g
     Lifecycles (10-90% sinusoidal)  >1‘000‘000’000
     Temperature sensor & memory  -
     Focal tuning range  +20 to +60 mm
     Wavefront error (@525 nm, 0mA)
     Optical axis vertical / horizontal
     <0.3 / <0.8 λ RMS

     Dispersion (at 20°C)

     486 nm  1.572
     589 nm  1.559
     656 nm  1.554
     800 nm  1.546
     1065 nm  1.541
     1550 nm  1.535
     Abbe number V  32

加入
EL-10-30-LD

Electrical type, low dispersion, C.A. 10mm

  •  Clear aperture  10 mm
     External diameter  30 mm
     Thickness  10.7 mm
     Weight  22.6 g
     Lifecycles (10-90% sinusoidal)  >1‘000‘000’000
     Temperature sensor & memory  -
     Focal tuning range  +45 to +120 mm
     Wavefront error (@525 nm, 0mA)
     Optical axis vertical / horizontal
     <0.2 / <0.5 λ RMS

     Dispersion (at 20°C)

     486 nm  1.302
     589 nm  1.300
     656 nm  1.299
     800 nm  1.298
     1065 nm  1.297
     1550 nm  1.296
     Abbe number V  100

加入
EL-10-30-C-LD

Electrical type, low dispersion, C.A. 10mm, C-mount

  •  Clear aperture  10 mm
     External diameter  30 mm
     Thickness  20 mm
     Weight  34.1 g
     Lifecycles (10-90% sinusoidal)  >1‘000‘000’000
     Temperature sensor & memory  Yes (SE97B)
     Focal tuning range  +80 to +200 mm
     Wavefront error (@525 nm, 0mA)
     Optical axis vertical / horizontal
     <0.15 / <0.25 λ RMS

     Dispersion (at 20°C)

     486 nm  1.302
     589 nm  1.300
     656 nm  1.299
     800 nm  1.298
     1065 nm  1.297
     1550 nm  1.296
     Abbe number V  100

加入
ML-20-35-VIS-HR

Manual type, High refraction, C.A. 20mm, AR coating:400-700nm

  •  Focal tuning range @ 525nm  -40 … inf … +40 mm

     Dispersion

     nF (486.1nm)  1.572
     nD (589.3nm)  1.559
     nC (656.3nm)  1.554
     Abbe number V  31

加入
ML-20-35-VIS-LD

Manual type, low dispersion, C.A. 20mm, AR coating:400-700nm

  •  Focal tuning range @ 525nm  -80 .. inf .. 80 mm

     Dispersion

     nF (486.1nm)  1.302
     nD (589.3nm)  1.300
     nC (656.3nm)  1.299
     Abbe number V  100

加入
ML-20-35-NIR-HR

Manual type, High refraction, C.A. 20mm, AR coating:700-1100nm

  •  Focal tuning range @ 525nm  -40 … inf … +40 mm

     Dispersion

     nF (486.1nm)  1.572
     nD (589.3nm)  1.559
     nC (656.3nm)  1.554
     Abbe number V  31

加入
ML-20-35-NIR-LD

Manual type, low dispersion, C.A. 20mm, AR coating:700-1100nm

  •  Focal tuning range @ 525nm  -80 .. inf .. 80 mm

     Dispersion

     nF (486.1nm)  1.302
     nD (589.3nm)  1.300
     nC (656.3nm)  1.299
     Abbe number V  100

加入
EL-E-4

Electrical Lens Driver

  •  Dimensions (L x W x H)  77 x 19 x 13 mm
     Weight  11g
     Interface to PC  USB Type A
     Interface to lens  0.5mm pitch 6 way FPC connector

     

加入

Working principle

The Fast Electrically Tunable Lens is a shape-changing lens. It consists of an injection- molded container, which is filled with an optical fluid and sealed off with an elastic polymer membrane. The deflection of the lens is proportional to the pressure in the fluid. The Fast Electrically Tunable Lens has an electromagnetic actuator that is used to exert pressure on the container. Hence, the focal distance of the lens is controlled by the current flowing through the coil of the actuator.
.

Fast Electrically Tunable Lens EL-6-18 Series:

Mechanical Dimensions (unit: mm)

Transmission range

Both the optical fluid and the membrane material are highly transparent and hardly absorbing in the range of 250 – 2500 nm. As the membrane is elastic it cannot be coated using standard processes, hence a reflection of 3 – 4% is to be expected. The standard cover glasses have a broadband anti-reflection coating for visible light.

Transmission spectrum of the EL-6-18 for standard VIS coated cover glasses (400-700 nm)

 

Step response time

The rise time on a current step is about 2 ms. However, it takes about 10ms until the lens has fully settled. The following graph shows the optical response on a current step measured using the astigmatic lens approach with a cylinder lens and a quadrant diode.

Optical response of the EL-6-18 to a current step from 21 to 63 mA and back

 

Focal length versus current

The focal power of the EL-6-18 increases with current. The starting point at zero current is set during production and can be varied from lens to lens. The slope of the focal length decrease is influenced by the mechanical properties of the membrane, which can also be varied on request to achieve different ranges of focal length. In open loop systems, a calibration of the lens with look-up tables is recommended.

Typical relation of focal length to current of the EL-6-18

 

 

Fast Electrically Tunable Lens EL-10-30 Series:

 Absolute maximum voltage  5 V
 Control current  0 to 300 mA
 Power consumption
 0 to 1.1 W
 Response time (10%-90% step)  <2.5 ms
 Settling time
 <15 ms
 Lens type  plano-convex
 Optical damage threshold @ 1064 nm
 10 kW/cm2
 Centration  <2 arcminutes
 Polarization  preserving
 Storage temperature  [-40,+85] °C
 Operating temperature  [-20,+65] °C

 

Housings

The EL-10-30 comes in two different housings: Compact and C-mount. While the compact housing is preferably mounted in a 30 mm ring, the C-mount housing has threads on either side. Furthermore, the C-mount version accommodates space to insert an offset lens of 12 or 12.7 mm diameter. The working principle of both versions is identical.

Mechanical drawing of the compact EL-10-30 (unit: mm)



Mechanical drawing of the EL-10-30-C (unit: mm)

 
Transmission spectrum of the EL-10-30 for custom narrow-band coatings

 

Focal length versus current

The focal length of the EL-10-30 decreases with increasing current. The starting point at zero current is set during production and can be varied from lens to lens, whereas the maximal value is 500 mm. The slope of the focal length decrease is influenced by the mechanical properties of the membrane, which can also be varied on request to achieve different ranges of focal length. In open loop systems, a calibration of the lens with look-up tables is recommended.

Typical relation of optical power (in diopters) to current of the most common
EL-10-30 variations. The error bars show the standard deviation from lens to lens.

 

Transmission range

Both the optical fluid and the membrane material are highly transparent and hardly absorbing in the range of 250 – 2500 nm. As the membrane is elastic it cannot be coated using standard processes, hence a reflection of 3 – 4% is to be expected. Cover glasses can be coated as desired. The figures below show the transmission spectrum for our two standard broad-band coatings (visible and near
infrared) as well as two custom narrow-band coatings:

Transmission spectrum of the EL-10-30 for standard broad-band coatings

The following graph represents the transmission of the lens material only2 (i.e. assuming perfect cover glasses).

Transmission of the EL-10-30 assuming 100% transparent cover glasses

 

Wavefront quality

In principle, Optotune’s focus tunable lenses exhibit a spherical lens shape. As the membranes used are elastic, the lens shape is influenced by gravity. With the lens lying horizontally (optical axis vertical) the RMS wavefront error of the EL-10-30 Series lenses is currently in the order of 0.1 λ (measured at 525 nm), allowing for high quality imaging e.g. in microscopy. With the lens standing upright (optical axis
horizontal) a Y-coma term must be added.

Wavefront measurement of a typical EL-10-30-VIS-LD and EL-10-30-C-VIS-LD
(at 525 nm and 80% of clear aperture, defocus, tilt & sphere excluded)

 

Response time

The rise time on a current step is about 2.5 ms. However, it takes about 15 ms until the lens has fully settled. The following graph shows the optical response on a current step measured using the astigmatic lens approach with a cylinder lens and a quadrant diode.

Wavefront measurement of a typical EL-10-30-VIS-LD and EL-10-30-C-VIS-LD
(at 525 nm and 80% of clear aperture, defocus, tilt & sphere excluded)

 

Life time

As the EL-10-30 has been released in June 2010, there is limited lifetime information available. However, the lens has passed relevant environmental and accelerated aging tests as outline in the table below.

Test
EL-10-30
 Mechanical cycling:
 40 million full-range cycles (0 to 300 mA rectangular, at 10 Hz)
 5 billion sinusoidal cycles at resonant frequency
 40.4
 High temperature test:
 85±2°C; rel. hum. <6% for 168 hours, non-operational
 61.7
 Temperature cycling test:
 -40°C / +85°C for 30 min each, 3 min transition time, 100 cycles
 88.3
 Damp heat cycling test:
 25°C / 55°C at 90-100% relative humidity, 3 hour transition time,
 24h per cycle (9h plus transition time each), 18 cycles
 94.8
 Shock test:
 800g for 1ms duration, 5 pulses in each direction (30 pulses in
 total)
 95.1
 Solar radiation test:
 1120 W per m2 (IEC 60068-2-5), 8 h irradiation & 16 h
 darkness, 10 cycles
 95.6

 Environmental tests performed on the EL-10-30
 

 

Manually Tunable Lens ML-20-35

 External diameter  35 mm
 Clear aperture1  20 mm
 Thickness
 8 mm
 Weight  11.35 g
 Lifecycles
 >100‘000
 Lens type  from plano-convex to plano-concave
 Optical damage threshold @ 1064nm
 10 kW/cm2
 Polarization  Preserving
 Storage temperature  [-40,+85] °C
 Operating temperature  [-20,+65] °C
 Lens diameter used for characterization  80 % of clear aperture
 Temperature  20° C

1Recommended useful aperture is 80% of clear aperture.


Mechanical drawing (unit: mm)


Transmission spectrum of the ML-20-35 with standard broad-band coatings

 

Electrical Lens Driver 4

● Current control range up to -290 to +290 mA with 12 bit precision
● Drive frequencies from 0.2 to 1000 Hz (rectangular, triangular or sinusoidal)
● I2C sensor read-out e.g. for temperature compensation
● USB powered
● Driver software in Windows 7
● Available with or without housing

 

Relevant on-board components

Current source with 12 bit precision (Analog Devices ADN8810)
Microcontroller 8-bit, 16 MHz with 32 KB Flash (Atmel ATmega32U4)
6-way FPC connector (Molex 503480-0600)

 

Maximum current

The maximum current of the driver is limited to either 290mA or 2.8V divided by the resistance applied.