Many applications (such as optogenetics, photoactivation, and photostimulation etc) call for precise spatial, temporal and/or spectral control of light. For instance, optogenetics is a technology that allows one to investigate behaviours of neurons and their circuits, by precisely delivering light - of different colors and with high spatial and temporal resolutions - to stimulate/silence selected neurons. In addition, there may also be a need to control neural activity independently and/or simultaneously at different locations. Mightex’s Polygon400 Patterned Illuminators are specifically designed for such applications.

Pattern Illumination Performance & Temporal Control

Polygon400 integrates the state-of-the-art spatial light modulators and high-power LEDs using a proprietary Etendue-preserving optical design to deliver high-intensity illumination patterns with diffraction-limited resolution. A Texas Instruments’ DLP spatial light modulator is used to display a user defined image pattern. At the heart of the Polygon400 is a unique optical system that carefully delivers light from LED sources to the DLP panel and then through a microscope to the specimen plane. Such a systematic approach makes it possible to achieve maximum optical intensity while maintaining diffraction-limited imaging performance.

Temporal performance is a key to many intended applications for Polygon400. With a frame rate of more than 4,000 fps, fast-switching LEDs, and compatibility with TTL trigger, Mightex Polygon400 can deliver illumination patterns with micro-second precision.

Software & Microscope Interface Options

The free PolyLite software allows users to generate illumination patterns as well as control illumination intensity and timing. The software also supports alignment between illumination patterns and images acquired through any digital cameras on a microscope. For optogenetics related applications, a dedicated software PolyScan is available and can be purchased separately. In addition, Mightex's Polygon400 is also supported by Nikon's NIS Elements software.

Mightex Polygon400 is designed to be easily inserted into the infinity path of a microscope. For inverted microscopes, the Polygon400 is usually mounted in place of the fluorescence illuminator. The filter cubes used for fluorescence observation folds Polygon400 beam into the microscope light path. A spare C-mount camera port can also be used for installation of a Polygon400. For upright microscopes, we provide a beam combiner cube to be inserted below the binocular/trinocular unit. The dichroic or mirror in the beam combiner directs the Polygon400 beam into the microscope light path.

Three Polygon400 Series

Currently, Mightex offers three (3) series of Polygon400. With an "I"-Series Polygon400, customers may specify up to three LEDs in the range of 400nm to 700nm to be included in the built-in light source engine.

The "E"-Series Polygon400 bypasses the internal LED controller and allows users to directly control the built-in LEDs through external LED drivers for more advanced control of the LED sources. The cathodes and anodes of built-in LEDs are connected to a multi-pin connector on the back panel of Polygon400.

A lightguide-coupled "G"-Series Polygon400 is also available where any light sources such as LEDs, lasers and arc lamps can be used for illumination. Note that the "G"-series does not have built-in LEDs. Instead, it accepts external light source(s) coupled by a common 3mm-core lightguide with ferrule diameter of 5mm and ferrule length of 15mm or greater. The features supported by the three series are as summarized in the table below.

1. When used with an external light source controller with TTL input trigger;
2. When used with an external light source controller with analog-input control capability;
3. When used with an external light source controller that supports arbitrary waveforms.
4. Depends on the functionality of the customer's laser driver.

Why External LED Controllers?

External LED controllers enable several important features not supported by the internal LED controller. One can achieve higher dynamic range, higher intensity resolution(>10bits), higher peak current in pulse mode, and faster response(<10µs). The use of external LED controllers also makes it possible to control LED timing independent of the micromirror array. For example, while the micromirrors stay at a constant position, the LEDs can be modulated to generate desired intensity profile. On the other hand, when needed, strict synchronization between the LEDs and the micromirrors can be achieved via the external trigger signals provided by the Polygon400.

Mightex supplies a variety of LED controllers that can be used with the “E” and "G" Series of Polygon400. Polygon400 software already includes synchronization features to support Mightex BLS- series LED controllers. For third-party LED controllers, synchronization can be implemented via trigger signals or Polygon400 SDK

Projection Area and Pixel Resolution (at 1x magnification)

To calculate illumination area and pixel resolution at the specimen, simply divide the above numbers by the magnification of the objective. For example, under a 10x objective on an Olympus microscope, the illumination area will be 0.78mm x 1.39mm with a pixel resolution of 1.62µm.

Available LED Wavelengths and Output Power

(on the Specimen Under Microscope in Pattern Sequence Mode)

1. Preliminary estimation. At specimen under a 20 x 0.75NA Olympus objective.

Control and Timing

Maximum Optical Input Power (for Polygon "G" and "F" series): 3W (<10 second pulse width with duty cycle of 20% or less)
Recommended Wavelenght Range: 400nm and longer

Currently, Mightex offers three (3) series of Polygon400 Patterned Illuminator. See below chart for their descriptions

Use the following part number configuration guide to build the Polygon400 Patterned Illuminator that best fits your application.

*. Microscope adapter or mounting ring/plate is required. Sold separately.

Examples

1. A Polygon with 470nm/530nm/590nm built-in LEDs, external controller, C-mount interface has part number DSI-E-0470-0530-0590-00C.
2. A lightguide-coupled Polygon for connecting to Nikon LAPP attachment has part number DSI-G-LAPP.
3. A Polygon with 470nm/590nm built-in LEDs, external controller, standard interface style has part number DSI-E-0470-0590-000.

Note: For "I" and "E"-Series, up to three (3) wavelengths can be selected, but certain combinations are not possible.

• Polygon400　オプトジェネティクス用イルミネータ

Polygon400 installation guide