I attended the ODF ’18 Lens Design Conference :)

I went to Hiroshima, Japan, to attend an optics conference. It was a great experience, and I learned a lot. I have to say that there was a lot of presentations on Freeform surfaces and Freeform optics, so that may be something that we can investigate further.

Want to hear about one of the more focused conferences I’ve attended?

Back ground on ODF: What kind of conference is it?

The International Conference on Optics-photonics Design & Fabrication (ODF) is a once every two years conference that is held in Asia and Europe.

For example, ODF 14 was held in Itabashi district of Tokyo, Mecca of optics. Companies such as Asahi (later Pentax) and Topcon started their companies there.

ODF 16 was in Weingarten, Germany, and unfortunately, I couldn’t attend.

This year, the conference was held in Hiroshima, Japan. Hiroshima is such a nice place to hold the event, the city exemplifies peace and this is what we all want to have.

When the conference is held in Japan, the organizers are the Optical Society of Japan, and they also organized the ODG conference where I presented about lens design, and got to meet Prof. Shuji Nakamura.

I really think that the 21st century is the age of optics, and we can see optics in all sorts of places. As such, I think that optics is a discipline that will thrive for a long time. Since entering the 21st century, the optical technology like optical fibres, CCDs, Blue LEDs, optical tweezers, ultra resolution microscopes, have received Nobel prizes.

Also, for ODF, it used to be called the “Optical Design and Fabrication”, but now it includes the word “photonics”, and I see “optics” shifting into “optics and photonics”. In that sense, the line between optics and photonics is blurry and can mean different things to different people.

Overview of the conference

Since the ODF conference is about lens design and fabrication. It is perfect for lens designers that want to dig deep into the manufacturable aspects of optics, and not just the theory.

A purely theoretical conference may treat actual products as secondary, and pure manufacturing might not get into the theory. Many presentations at this conference start with lens design and theory and then go into actual manufacturing of the lens or optical system, and does not end in theory alone.

This year and the last time I attended, I noticed that there was not a certain part of optics that was covered more than another, and found that a lot of disciplines were relatively evenly represented.

The best part about ODF is that we can learn the cutting edge of optics from a design and fabrication standpoint, and as an optical engineer these are very valuable.

There are professors from Arizona and Rochester among other top universities that were in attendance, and also top optics companies such as Nikon, Ricoh, and Fujifilm, while top technology companies like Fujitsu, NTT, and Sumitomo were also in attendance. I truly diverse mix of attendees.

Topics in the conference that caught my eye, and some talks of note

This year there were many interesting topics, but as a whole, there was one topic that caught my eye as far as lens design in my mind.

Freeform surfaces.

The Emergence of Freeform Optics: Design for Manufacture 28PL-02

This talk was by Jannick Rolland, the Brian J. Thompson Professor of Optical Engineering at Rochester, a leader in Freeform optics and head of The Center for Freeform Optics (CeFO)

The presentation was about the best freeform to use from a systems perspective, and there was deep research into the different forms of freeform surfaces that can be used for a reflective mirror imaging system.

The efficient cancellation of the odd aberrations was used as a focal point for optimization, and the various possibilities of freeform surfaces were investigated.

The surfaces used were Zernike Surfaces, and I think that there is also the possibility to investigate further with different freeform surfaces as well.

In the end, just like in ODF style, Professor Rolland finished up her talk with the challenges in the manufacturing of such a reflective freeform surface, and what kind of tolerances and surface roughness are needed for the system.

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h3>Using Swarm Intelligence: A Novel Approach to Automatic Lens Design 28S1-04

Although this talk was not about freeform lenses per se, it was a next level implementation of optimization algorithms.

We all know that the starting point is crucial for lens design. If we don’t have a good starting point for our lens design, we may end up in a local minimum and not get the very best design.

So far, this part of lens design is left to human experience and intuition. The talk was about Swarm intelligence, kind of like a swarm of birds or a swarm of fish. These fish or birds are all going in a general direction, but if one happens to get stuck in some way, the rest of the pack can get to their destination.

We can think of normal optimization like one fish, and Swarm Intelligence optimization like a group of fish.

How it works is also interesting. The merit function is evaluated for multiple points in a swarm, and those multiple points serve to calculate the group velocity of the merit function which acts as a cloud of merit functions in a sense. The swarm is used to find the best region of optimization, and then a more local optimization is used as the final step.

The examples varied from classic lenses like the Double Gauss and the retrofocus lens, and even a Freeform surface optic.

Freeform Optics for Virtual Reality 28S1-05

Professor Juan C. Miñano presented a Head Mount Display (HMD) optic. There are a few issues that need to be addressed with HMDs, which are the Field of View (FOV), resolution and the size.

He illustrated an approach of finding the best solution balancing the three form an optical perspective. Using ideas from a fly-eye lens, he has fabricated a multi freeform prism for HMDs.

http://www.limbak.com/technology/

Micro-optical Free-Forms: Design and Fabrication 28S1-06

U. Zeitner from Fraunhofer presented an innovative optical design by combining two novel lens systems, the freeform lens and the microlens array (MLA). They combined the MLA and freeform by making the surfaces of each individual lens of the MLA as a freeform. This gives a degree of freedom not possible with simple lenses in the lens array.

This technology was used in the headlamp for motor vehicles, where the cutoff line and shape of the light distribution is not only important but a legal requirement.

One final point, there was an invited speaker from Mazda talking about for autonomous driving and the car industry. I think it was a good get because being in Hiroshima city, it was close their headquarters in Kure.

The attendees of ODF

Although I love Photonics West, the photonics industry is so large that there can be an overwhelming amount of information and it is hard to sift through the conference agenda just to find the topics that are of note to you. One thing that is great about ODF is that the variety is niche enough so that each topic can be discussed much deeper than a typical large scale conference. That’s just how hard it is to find a presentation about lens design in optics and photonics.

There were about 240 people in attendance. Of them, there were 140 from Japan, 50 from Taiwan, 10 from Germany / South Korea / USA, and 5 from China and India. I met a few Italian attendees. Obviously, the representation from Japan and Asia is high due to the venue, but there is a truly diverse amount of individuals there.

There were over 50 presentations and over 70 posters. The great part about a conference the size of ODF is that there is only one conference room. No need to switch locations to see a talk of interest, no way to miss a talk, and an abundance of opportunity to talk about every talk with the people in attendance, since we are all listening to the same presentations.

The feeling I got was that people that study the cutting edge lens design like freeform surfaces and diffractive optical elements (DOEs), the studies are very very deep at Universities and research institutions. This type of research can lead directly to the development of autonomous vehicles and AR/VR industry and even the Industry 4.0 standard.

Notable names I got to meet at the conference

Notable names in lens design such as Prof. Juan Miñano was in attendance. I was flattered that he remembered me from when we met in Itabashi in 2014.

Akira Yabe, author of Optimization in Lens Design and independent lens designer was also in attendance.

Unfortunately, Prof. Forbes was not in attendance this year.

And the organizer, Prof. Masato Shibuya, formerly of Nikon and inventor of the phase shift AF system, and current professor at Tokyo Polytechnic University, kicked the conference off.

Professor Shibuya opened the conference with some nice words.

Optical surfaces such as freeform optics and diffractive optical elements are different from the classical optical surfaces, and there is a need to further develop the optical design and the fabrication of these optical surfaces and elements.

Large changes in the industry start from deep discussions on even the smallest of problems. My hope is that you all have small questions and have a deep discussion during this conference.

Among the Japanese attendees, I noticed many people from past optical symposia and the ODG conference where I presented last year.

On the other hand, I did notice that there was a large gap in the knowledge of lens design (not optics, lens design) in between attendees. I suspect that this is because lens design is not as mainstream of a science in academia to the level of Quantum mechanics or Electrodynamics such as in Physics.

What kind of conferences do you like?

As is often the case, I have been extremely fortunate to be able to attend both large conferences and very small conferences as well. These niche conferences are a great place to talk with a more focused group of people that share more common knowledge with you if we choose our conferences carefully.

Being able to connect with so many people that were so close to my field is always a great experience. I feel privileged to be able to attend these conferences. These people are either top of their field or very active in their field, and there was so much to learn from so many people, and I like to think that I was able to hold my own in conversation with them.

Are there any lens design conferences that you have gone to that were particularly memorable? I’d love to hear some of your experiences 🙂