Jamin-Lebedeff Interference Contrast Microscopy

[Wes]

After searching for a while I finally found a complete Jamin-Lebedeff interference set that I could install on my Phomi. Its a system of condensers and objectives where each pair contains an optically identical crystal used for beam splitting and recombining. A reference beam is compared to a sample beam passing through an object of interest which can be used to derive information about the object thickness, refractive index, dry mass and properties. While DIC compares an object with itself the JL system compares the object to an adjacent area in the field of view. An interesting side effect of the system is that it produces interference colors that depend on the optical path difference between object and reference.


Here are some of the effects I was able to observe with the system.



A dust fiber in a droplet of water, 10x




Oil droplets on a dirty slide, 10x




Pediastrum, 40x




Navicula lyra, 40x




DNA, 10x



DNA, 10x



Pediastrum, 40x


Tiny ciliates maybe cyclidium, 40x


DNA with impurities, 10x


DNA with impurities, 10x


Unfortunately these are no longer manufactured as they were not commercially lucrative and were therefore discontinued from the Zeiss program (there are some other variants of a double beam microinterferometer such as a Mach-Zender design by Leitz that also had a JL variant, Interphako by Zeiss Jena and a few others).

Best regards
Wes

[BramHuntingNematodes]

wow neat. I want to get a big framed print of the michel-levy birefringence chart sometime

[Zuul]

While I find these really cool from an aesthetic perspective, I’m struggling a bit to see the practical application of this technique. What would this method reveal that others do not?

[Scarodactyl]

Thanks for sharing this! I had never heard of this technique but the results seem quite cool.

[microb]

Cool.

https://www.nature.com/articles/lsa201356.pdf

[MicroBob]

Hi Wes,
congratulations on this rare piece of equipment!
One probably has to think about it for a while to identify the full range of uses. As these kits are rare there is no estabished path to trod along, at least not in amateur use. In the german forum a guy has assembled a Zeiss Jena system, if they do the same you might work together.

Bob

[Hobbyst46]

Spectacular images !

[Wes]

Many thanks to everyone for the interest.

While I find these really cool from an aesthetic perspective, I’m struggling a bit to see the practical application of this technique. What would this method reveal that others do not?

It allows you to measure the phase difference between an object of interest and the surrounding medium. Because the phase difference is directly proportional to the difference of the products of refractive index and thickness (this product is called optical path) between the object and medium you can use this information to derive one or the other component of this product.. You can calculate the dry mass of a cell nucleus for example.

Hi Wes,
congratulations on this rare piece of equipment!
One probably has to think about it for a while to identify the full range of uses. As these kits are rare there is no estabished path to trod along, at least not in amateur use. In the german forum a guy has assembled a Zeiss Jena system, if they do the same you might work together.

Bob

Hi Bob,

I did not know that, can you send me a link to this thread (here or via PM).

[Wes]

I thought I'd give a brief description of how the JL microscope actually works.

A plane polarized wavefront enters beamsplitter S (in the condenser) where it is split into two orthogonally polarized and laterally displaced rays. These pass a half-wave plate that rotates their vibration plane by 90˚ and one beam passes through the object (O) and is therefore retarded compared to the reference beam passing through the embedding medium. The reference and sample beam are combined on a common axis of propagation by an equivalent birefringent crystal (C) mounted directly on the front lens of the objective. The sample ray is additionally split to produce a ghost image of the object (one has to rotate the stage to get this out of view). The main object is in the center of the FOV (2), the reference area (3) and ghost image (1) are on a diagonal line relative to the main object field.

Using a Senarmont compensator you can measure the optical path difference between an object (be it iso- or anisotropic) by recording the rotation of the analyzer required to turn the object to maximum darkness.

[MichaelG.]

I want to get a big framed print of the michel-levy birefringence chart sometime

Bram,

There is a good version in the PDF of a Zeiss document [page 4 of 7]
... seems to be in vector graphics, so enlarges nicely.

70_2_0110_e_michel_levy.pdf

I can’t locate the file via zeiss.com, but just Google search for that filename, or use: https://applications.zeiss.com/C1257929 ... l_levy.pdf

MichaelG.

[BramHuntingNematodes]

I want to get a big framed print of the michel-levy birefringence chart sometime

Bram,

There is a good version in the PDF of a Zeiss document [page 4 of 7]
... seems to be in vector graphics, so enlarges nicely.

70_2_0110_e_michel_levy.pdf

I can’t locate the file via zeiss.com, but just Google search for that filename, or use: https://applications.zeiss.com/C1257929 ... l_levy.pdf

MichaelG.

nice

[hsi100]

Spectacular images.
Any idea where I can get one as it seems out of production?
I did find this paper: https://journals.plos.org/plosone/artic ... ne.0227096

[Wes]

Spectacular images.
Any idea where I can get one as it seems out of production?
I did find this paper: https://journals.plos.org/plosone/artic ... ne.0227096

Thanks hsi100,

You can find a JL set on Ebay.

[microb]

After searching for a while I finally found a complete Jamin-Lebedeff interference set that I could install on my Phomi. Its a system of condensers and objectives where each pair contains an optically identical crystal used for beam splitting and recombining. A reference beam is compared to a sample beam passing through an object of interest which can be used to derive information about the object thickness, refractive index, dry mass and properties. While DIC compares an object with itself the JL system compares the object to an adjacent area in the field of view. An interesting side effect of the system is that it produces interference colors that depend on the optical path difference between object and reference.

What does the adapter that goes in front of the objective lens look like?

[Wes]

After searching for a while I finally found a complete Jamin-Lebedeff interference set that I could install on my Phomi. Its a system of condensers and objectives where each pair contains an optically identical crystal used for beam splitting and recombining. A reference beam is compared to a sample beam passing through an object of interest which can be used to derive information about the object thickness, refractive index, dry mass and properties. While DIC compares an object with itself the JL system compares the object to an adjacent area in the field of view. An interesting side effect of the system is that it produces interference colors that depend on the optical path difference between object and reference.

What does the adapter that goes in front of the objective lens look like?

The objective has a quick change ring that slides into a dedicated nosepiece. The crystal is mounted directly on top of the front lens and both are housed in a rotating head that can be rotated +/- 5˚ to achieve interference.

[microb]

Another reference. See page 33: http://www.photonics.intec.ugent.be/edu ... v2ch17.pdf

[microb]

The objective has a quick change ring that slides into a dedicated nosepiece. The crystal is mounted directly on top of the front lens and both are housed in a rotating head that can be rotated +/- 5˚ to achieve interference.

Thanks. Is that objective something like 4x so the nose fits into the open work distance? Or are optics in that nose and that's a high magnification objective?

I'm trying to figure out if I can put a birefringence prism in front of like a 32mm working distance Mitutoyo ULWD objective for example.

[Wes]

The objective has a quick change ring that slides into a dedicated nosepiece. The crystal is mounted directly on top of the front lens and both are housed in a rotating head that can be rotated +/- 5˚ to achieve interference.

Thanks. Is that objective something like 4x so the nose fits into the open work distance? Or are optics in that nose and that's a high magnification objective?

I'm trying to figure out if I can put a birefringence prism in front of like a 32mm working distance Mitutoyo ULWD objective for example.

There is a 10x, 40x and 100x (the one in the picture is the 100x). The working distance is quite small because of the crystal in front.

What is your aim exactly, what do you want to achieve with a birefringent prism in front of your objective?

[microb]

The objective has a quick change ring that slides into a dedicated nosepiece. The crystal is mounted directly on top of the front lens and both are housed in a rotating head that can be rotated +/- 5˚ to achieve interference.

Thanks. Is that objective something like 4x so the nose fits into the open work distance? Or are optics in that nose and that's a high magnification objective?

I'm trying to figure out if I can put a birefringence prism in front of like a 32mm working distance Mitutoyo ULWD objective for example.

There is a 10x, 40x and 100x (the one in the picture is the 100x). The working distance is quite small because of the crystal in front.

What is your aim exactly, what do you want to achieve with a birefringent prism in front of your objective?

The pictured objective did look like a higher res (100x). I didn't think a prism would fit in the working distance.

I'm just wondering about making a set up. The prisms used would be easier design to make before trying two angled cemented like a Wollaston prism.

[Wes]

Thanks. Is that objective something like 4x so the nose fits into the open work distance? Or are optics in that nose and that's a high magnification objective?

I'm trying to figure out if I can put a birefringence prism in front of like a 32mm working distance Mitutoyo ULWD objective for example.

There is a 10x, 40x and 100x (the one in the picture is the 100x). The working distance is quite small because of the crystal in front.

What is your aim exactly, what do you want to achieve with a birefringent prism in front of your objective?

The pictured objective did look like a higher res (100x). I didn't think a prism would fit in the working distance.

I'm just wondering about making a set up. The prisms used would be easier design to make before trying two angled cemented like a Wollaston prism.

The 100x has a NA of 1.0 (comparatively low for 100x objectives in general) as the front lens had to be elevated a bit in order to fit the prism in there. If you could make Wollaston prisms and such you could probably make quartz wedges too. I imagine lots of people would be interested in buying one.