Epi-Illumination Layer

The Epi Illumination Layer is used to couple a wide range of illumination sources into the openFrame’s infinity space.

Immediately under the Focus Layer is the first layer that allows illumination sources to be coupled into the openFrame microscope. This can range from basic single wavelength LED illumination to substantially more advanced illumination systems such as laser scanners used for TIRF, FRAP or photomanipulation experiments. A key defining feature of all the options is that any filter cubes or mirror mounts can be individually tip-tilt adjusted. This allows for straightforward optical registration of all illumination channels, to ensure zero pixel shift between different illumination paths, especially important for demanding applications such as TIRF.

Light sources can be coupled directly, free space, or remotely via a liquid light guide or multimode / singlemode fibre. The illumination can be masked using Cairn's unique dual-control adjustable rectangle aperture, to match photon exposure to the camera sensor and avoid corner bleaching when tiling images.

Single Epi Layer

The Single Epi Layer provides a tip-tilt adjustable input for a single illumination source.

On the openFrame the Single Epi Layer provides a means of coupling a single illumination source to the microscope. This is the preferred solution for applications that only require a single illumination source. It is also the recommended solution for multi-modal illumination, for example when combining widefield fluorescence imaging with simultaneous photostimulation. In such cases, the second illumination source would mount on a Single or Dual Epi Layer in the Flexi Layer position (see below). 

When using the Single Epi Layer, there are two possible mounting points located on opposite sides of the module. While only one of these is used at a time, the two positions provide more flexibility and avoid spatial conflicts with components on other layers when bulky illuminators are used. It also allows a custom illuminator to be built in parallel without decommissioning the microscope from it's day-to-day use 

At the heart of the layer sits a filter cube that typically holds the dichroic mirror used to couple the illumination light into the central optical path of the openFrame. This filter cube is tip-tilt adjustable, to allow for precise alignment of the illumination. This is easiest achieved by viewing the illumination live on the camera and adjusting the resulting image to a target image.

Dual Illumination Layer

The Dual Epi Layer enables the stable and easy switching between two illumination sources.

The openFrame Dual EpiLayer allows motorised or manual switching either between filter cubes (with up to three positions) or between two illumination inputs. The ability to switch between illumination inputs allows the building of powerful multi-functional systems on a single compact microscope frame. If two different illumination inputs are to be used sequentially, there is no need to add additional layers or external combiners to achieve this. 

The Dual Epi Layer has two input ports on opposing sides. Each of these can have an illumination device connected. Switching between the connected devices is achieved by simply selecting the corresponding filter cube position -  through the push of a button or software command (if you prefer doing this manually, there is a physical slider present as well).

The core of the layer is the sliding rail of three filter cube holders. Each will take one cube, which can be oriented so that it couples either the one or the other illumination port into the central optical path of the openFrame. Two of the filter cubes can be individually tip-tilt adjusted, so they are registered to each other (and the central cube if present) with sub-pixel precision. This is easiest achieved by viewing the illumination live on the camera and adjusting the resulting image to a target image.