ASSEMBLY_CUBE_Beamexpander

Integrated Telescope/Beam-Expander Cube

This is the repository for the Integrated Telescope Cube.

To acquire the STL-files use the UC2-Configurator. The files themselves are in the RAW folder. The module can be built using injection-moulded (IM) or 3D-printed (3DP) cubes.

Purpose

It adapts a very small beam-expander to the UC2 system.

Sometimes one need to increase the diameter of an illuminating beam. This is necessary for the Light-sheet microscopy setup for example. Here we have a laser-pointer which comes with a relatively small beam-diameter of about 2mm. By using a telescope, this can be magnified by a factor of e.g. 8 which results in a beam-dimeter of 16 mm. This is necessary to overfill the aperture of the following illumination objective lens.

In order to achieve this, we first need to focus the beam with a low focal length lens (e.g. cellphone lens, f'=3mm) and then re-collimate the lens with a second lens with a larger focal length e.g. f'=25 mm.

We designed a telescope where an iPhone 5 lens and an ordinary 25mm lens can be inserted in an adapter, which finds its place inside an ordinary UC2-cube as visualized in the image above.

Properties

• design is derived from the base-cube
• the adapter for the telescope can be adjusted for different magnifications and lenses
• the beam height can be adjusted by sliding the telescope along the axis
• the degree of collimation can be adjusted beforehand * very cost-efficient beam-expander at a fairly good quality as the cellphone lens is diffraction limited (overall costs ~15€)
• Magnification : m=f_tl/f_ep = 25/3 = 8.33

Parts

The Bill of Materials is always the most up-to-date version!

3D printing parts

• No support needed in all designs
• Carefully remove all support structures (if applicable)

The Cube consists of the following components.

Default:

• IM Cube which houses the insert and adapts it into a UC2 setup.
• The Telescope which holds the two lenses adapts it to the base cube. For the 26,5 mm lens. (20_Cube_Insert_Beamexpander_astromedia_v3.stl)

Alternatives:

• 3DP Cube which will be screwed to the Lid. Here all the functions (i.e. Mirrors, LED's etc.) find their place (10_Cube_1x1_v3.stl) and 3DP Lid which closes the Cube (10_Lid_1x1_v3.stl) - find the details in ASSEMBLY_CUBE_Base
• The Telescope which holds the two lenses adapts it to the base cube. For the 20 mm lens. (20_Cube_Insert_Beamexpander_optikbaukasten_v3.stl)
• The Lens Adapter which is suitable for a lens with 12,7 mm diameter listed in the additional parts (20_Beamexpander_Lens_Adapter.stl)
• Custom Lens Adapter You might need a custom one or none at all, depending on the lens you use.

Additional parts

• Check out the RESOURCES for more information!
• iPhone 5 lens (separated from an iPhone camera spare part), f'=3mm 🢂
• 1× Achromat Lens, f' = 26,5 mm 🢂
• Alternative: biconvex/plan-convex lens, f'=20mm, diameter=12,7mm, thickness=4mm (Artikel 2107) 🢂

Assembly

• Remove the iPhone lens from the camera (a dedicated tutorial can be found in the UC2 Tutorial-Section (page 6).
• Insert the lenses inside the telescope adapter (orientation of the iPhone has to be the way, that the small aperture - hole - has to face the other bigger lens as indicated by the photo)
• Put the telescope inside the cube
• Close the cube accordingly (IM/3DP)
• Done!

Tutorial with images

Don't insert batteries in the laser yet!!

❕ This tutorial shows a UC2_v2 cube but the assembly of the insert is still the same. For assembly of the cube (IM/3DP) check the ASSEMBLY_CUBE_Base.

1. All parts to build the beam-expander:

2. Put both lenses into the beam-expander insert. Use the Lens adapter if necessary.

3. Put the pre-assembled (and optically aligned) insert in the base-cube and add the screws:

Alignment

❕ This tutorial shows a UC2_v0 cube and insert but the alignment procedure of the telescpe is still the same.

• Take the laser-pointer
• Point the laser towards the iPhone Lens
• Adjust the distance between the two lenses, so that the beam is collimated (=the beam diameter right after the telescope should not change over any distance)

Finetune the lens-distance (collimate the beam)

1. Add the centered laser to the grid like so:

2. Turn on the laser:

3. Optional: Align the laser (center with the screws)

4. Check the beam on a white piece of paper

5. Mark the position and diameter of the beam on the white piece of paper

6. Compare distance and diameter of laser spot at a distance far away

7. Adjust the position of the cellphone lens in the rail so that both spots have the same position and diameter (iterate - start at step 5 - until you're satisfied)

Safety

Attention, don't cut your fingers while removing the lens from the iPhone sensor!

Never (!) look into the laser pointer! It will damage your eye immediately!

• ATTENTION: NEVER WATCH DIRECTLY INTO THE LASER! EYE WILL BE DAMAGED DIRECTLY
• NEVER SWITCH ON THE LASER WITHOUT INTEDED USE
• BEAM HAS TO GO AWAY FROM ONESELF - ALWAYS!