Mitutoyo TAGLENS Liquid Tube Lens for Ultra Deep DOF

[RobertOToole]

Looks like this came out last year, I didnt know anything about it.

TAGLENS is a liquid tube lens uses a fast pulsed light and quick focus to scan at 70,000 x a second to create a deep focus image. Used for microscopy with M Plan APOs but not available for HR Plan APOs. Interesting concept. They don't mention resolution at all, or maybe I missed it, in any of the promo material.



https://www.youtube.com/watch?v=Z7QuloPC6KM


https://www.mitutoyo.com/webfoo/wp-cont ... 2277-1.pdf


https://mitutoyo.eu/application/files/3 ... ok_WEB.pdf

[RobertOToole]

Just checked eBay and there is one TAGLENS unit for $99, no returns. Joke. But someone in China did put the TAG LENS keywords on a normal M Plan UV 50x asking price $10,241.90 + $9.09 shipping.

Somethings never change.

[Beatsy]

Wow, that's a really interesting gizmo, and seemingly an answer to a long term daydream (faster capture of focus brackets), but...

At what price? Probably swoon-inducing.

The miniscule FoV (with relatively low resolution objectives) makes it significantly less desireable.

And 70k frames/sec must surely require some seriously monster lighting. I envisage every capture coming out as a picture of a black smoking hole!

[rjlittlefield]

TAGLENS is a liquid tube lens uses a fast pulsed light and quick focus to scan at 70,000 x a second to create a deep focus image.

Thanks for bringing this to my attention. I had not known of its existence either.

In reading the literature, I struggle a bit to separate what the device does from how it can be used, and how much of the latter is aspirational rather than demonstrated. (Good for everything from crowd surveillance to self-driving vehicles! I paraphrase from the concept diagrams: HERE, page 9.)

The Q & A section of https://mitutoyo.eu/application/files/3 ... ok_WEB.pdf, page 10, says that "The TAGLENS focal length changes continuously, and this action cannot be stopped. However, the functions of the sensors inside the TAGLENS body can be used to acquire data at the desired focal length only."

Elsewhere (https://www.mitutoyo.com/webfoo/wp-cont ... 2277-1.pdf, page 8 ), I read that

TAGLENS changes the focus point at high speed. However,
because the capturing time per frame is longer than the
focusing time, the images will have optically mixed focus
points from different heights, and the image will be blurred.

The software restores this blurred image to an entirely sharper
image from the upper surface to the lower surface by determining a
blurred amount estimate from the TAGLENS control parameter that
has been set in TAGPAK-C and information in the optical system and
then performing deconvolution processing. This is called the EDOF
image.

And finally, I read at https://www.mitutoyo.com/webfoo/wp-cont ... 2277-1.pdf, page 7, that

The ultrafast pulse illuminator 【PLS】 is new arrival. 【PLS】 is faster than the scanning speed of TAGLENS.
・ A focused image in any specified Z-position can be captured
without mechanical drive system within the observation range
at an extended depth of focus.
・ Multiple images focused in given Z-positions can be captured.
・ Each captured image is provided with a high-quality original
image.

Tracking down detailed specifications, I found https://www.mitutoyo.com/taglens/ which says that the lens resonant frequency is 70 KHz. I also found https://shop.mitutoyo.eu/web/mitutoyo/e ... heet.xhtml which says that the maximum frequency of the PLS is 75 KHz, with an optical pulse width from 50 ns to 100 ns. The PLS specs also say that the maximum light output is 30 lm, which I expect means 30 lumens average.

Putting all this together, I see two very different practical modes of operation:

• Use continuous illumination to capture a single image that integrates over the whole focus range, then deconvolve to recover sharpness (at the cost of adding noise).
• Capture a single image by flashing at the appropriate instant, then repeat that process as desired over multiple cycles of the lens.

As a not-practical mode of operation, I'll add that one might blast the subject with continuous illumination and record frames with an ultra high speed camera. However, it's going to be challenging to get a good combination of lateral and depth resolution, for example the Phantom TMX 75100 will give only 640x64 as 1.75 Mfps, which if I've worked the sums correctly is still less than 13 frames per half-cycle of the lens.

--Rik

[Macro_Cosmos]

TAG = Tunable acoustic gradient

US9946081B2
US9389343B2
US10101572B2
US10151962B2

It does autofocus and extended depth of field imaging (processed?), and it is able to compensate for common aberrations.

[RobertOToole]

TAG = Tunable acoustic gradient

US9946081B2
US9389343B2
US10101572B2
US10151962B2

It does autofocus and extended depth of field imaging (processed?), and it is able to compensate for common aberrations.

Wow MacroCosmos, good job digging those up!

To save people a couple of clicks:

https://patents.google.com/patent/US9946081B2/en?
https://patents.google.com/patent/US9389343B2/en?
https://patents.google.com/patent/US10101572B2/en?
https://patents.google.com/patent/US10151962B2/en?

Huge amount of technical details if someone has a lot of time to kill. I read like 2% and had to take a break

SUMMARY OF THE INVENTION
To overcome some of the aforementioned limitations, the present invention provides an adaptive-optical element termed by the inventors as a “tunable-acoustic-gradient index-of-refraction lens”, or simply a “TAG lens.” In one exemplary configuration, the present invention provides a tunable acoustic gradient index of refraction lens comprising a casing having a cavity disposed therein for receiving a refractive material capable of changing its refractive index in response to application of an acoustic wave thereto. To permit electrical communication with the interior of the casing, the casing may have an electrical feedthrough port in the casing wall that communicates with the cavity. A piezoelectric element may be provided within the casing in acoustic communication with the cavity for delivering an acoustic wave to the cavity to alter the refractive index of the refractive material. In the case where the refractive material is a fluid, the casing may include a fluid port in the casing wall in fluid communication with the cavity to permit introduction of a refractive fluid into the cavity. Additionally, the casing may comprise an outer casing having a chamber disposed therein and an inner casing disposed within the chamber of the outer casing, with the cavity disposed within the inner casing and with the piezoelectric element is disposed within the cavity.

In one exemplary configuration the piezoelectric element may comprise a cylindrical piezoelectric tube for receiving the refractive material therein. The piezoelectric tube may include an inner cylindrical surface and an outer cylindrical surface. An inner electrode may be disposed on the inner cylindrical surface, and the inner electrode may be wrapped from the inner cylindrical surface to the outer cylindrical surface to provide an annular electric contact region for the inner electrode on the outer cylindrical surface. In another exemplary configuration, the piezoelectric element may comprise a first and a second planar piezoelectric element. The first and second planar piezoelectric elements may be disposed orthogonal to one another in an orientation for providing the cavity with a rectangular cross-sectional shape.
The casing may comprise an optically transparent window disposed at opposing ends of the casing. At least one of the windows may include a curved surface and may have optical power. One or more of the windows may also operate as a filter or diffracting element or may be partially mirrored.

In another of its aspects, the present invention provides a tunable acoustic gradient index of refraction optical system. The optical system may include a tunable acoustic gradient index of refraction lens and at least one of a source of electromagnetic radiation and a detector of electromagnetic radiation. A controller may be provided in electrical communication with the tunable acoustic gradient index of refraction lens and at least one of the source and the detector. The controller may be configured to provide a driving signal to control the index of refraction of the lens. The controller may also be configured to provide a synchronizing signal to time at least one of the emission of electromagnetic radiation from the source or the detection of electromagnetic radiation by the detector relative to the electrical signal controlling the lens. In so doing, the controller is able to specify that the source irradiates the lens (or detector detects the lens output) when a desired refractive index distribution is present within the lens. In this regard, the source may include a shutter electrically connected to the controller (or detector) for receiving the synchronizing signal to time the emission of radiation from the source (or detector).

The piezoelectric material used for the tube 310 is lead zirconate titanate, PZT-8, and the filling fluid for the lens 300 is a Dow Corning 200 Fluid, a silicone oil. The piezoelectric tube 310 is driven by the controller 390 which includes a function generator (Stanford Research Systems, DS345) passed through an RF amplifier (T&C Power Conversion, AG 1006) and impedance matching circuit, which can produce AC voltages up to 300 Vpp at frequencies between 100 kHz and 500 kHz. Other impedance matching circuits could be used to facilitate different frequency ranges. Two different driving frequencies are used, corresponding to resonant and off-resonant cases, listed in Table I.

[Macro_Cosmos]

AO is not new at all, microscopists are only playing catch-up in the recent decade, compared to the astro-imaging field. Eric Betzig put it pretty well but his remarks were quite crude, so I will not quote him here.


At 2:32, without his usual swearing. There was an extended lecture where he used funny language.
This guy is pretty good at making analogies, imaging the galaxy is just imaging brains, where all kinds of aberrations are at play.

I was a part of a testing group back in 2018-2019 where they asked us if we see real advantages in adaptive optics, and what the desired price would be.
My supervisor said $5k (AUD), they said it will have to be in the low 5-digits, USD currency.

I was mainly interested in its real-time compensation of spherical and chromatic aberration. This is useful for super-resolution stuff.

If anyone wants to see real-world implementations of AO:
(I have only read up on microscopy use.)
Here is an implementation for fluorescence microscopy, translate the text, it should be alright: https://www.opticsjournal.net/Articles/ ... 3011e67676

Here is another used with a Clarity white light confocal module: https://www.biorxiv.org/content/10.1101 ... 8.225607v1
They said "confocal-like", but the Clarity module is a confocal scanner (though not conventional pinhole based, it uses slit discs), perhaps I am misunderstanding things.