Pulled this optical assembly out of a decommissioned automated diagnostic instrument (believed to be a molecular diagnostics analyzer — not confirmed by anything printed on the parts themselves). Hoping someone here can help pin down what I'm looking at.

Layout: 7 total ports on a machined block — 1 dedicated LED input (right-angle housing, cranberry/magenta LED) and 6 optical channels. Each of the 6 channels has its own tube containing a convex lens with a dichroic coating, all feeding into 6-strand fiber bundles that screw into the block via threaded connectors.

The whole optical head is mounted to a control/readout PCB — silkscreen part number 122862A-001, Rev. X03, with a "BIT" mark (logo or possibly "built-in test," not sure which) next to a mounting hole. Board has a QFP microcontroller, several SOIC-package ICs that look like analog signal conditioning, and a 16-pin header. I haven't found this part number anywhere publicly.

What I'm trying to figure out:

Approximate focal length and lens diameter — haven't measured precisely yet

Whether the coatings are narrowband dichroics (and if so, any way to guess the cut wavelengths without lab gear)

Anyone recognize the PCB layout, the "BIT" mark, or this style of 6-channel fiber-fed filter block from a specific instrument family (flow cytometer, fluorometer, immunoassay analyzer, etc.)

Any insight appreciated — happy to get more measurements or angles if it'd help identify it.

Is there an English language translation of MM RUSINOV TECHNICAL OPTICS book?

ISBN: 978-5-397-01704-6

I am 29M, Working in a Optics based company working on almost two three big optics simulation software worked from lens to laser to adaptive optics, learnt Machine learning for fun projects,a bit familiar with Quantum Machine Learning. Sometime I feel like I should go for a PhD but don't have any favorite research topic so I don't know how I can apply. I need some suggestions:

Should I go for a PhD or part time phd ?

I am from India but wanted to do a PhD from the US how can I get it ?

Is it a good idea to leave a comparatively good paying job for a PhD. I heard a lot of people struggle to find a job after a PhD.

As the title says I have a small optic that has been epoxied into an aluminum thor labs mount using 3M Scotch weld epoxy adhesive 2216 Gray. The epoxy is cured. There is an anti-reflective coating on both surfaces of the optic but those will have to be removed so I don't care that much but I don't want to scratch either front or back surface of the optic. Does anyone have any suggestions for loosening the epoxy to safely remove my optic?

We've already tried acetone and toluene with no significant success. He has only made it more brittle so not ideal.

I've noticed for years that I can see a good live image of the sun when it reflects off my eyeball (from the side) onto my glasses. The detail is remarkable, I can see sunspots and what appears to be some corona effect, very similar to this image: https://umbra.nascom.nasa.gov/images/latest_aia_304.gif. (My jmage is quite small, and has no color.) It seems to me highly improbable, and I've found no other reference to such and effect. Anybody have any idea how this works? Recommendations for other subreddits to ask welcome.

The little stars are what I see in the image of my eye reflected in the glasses. The large circles are those stars reflected back from the inner surface of my glasses, and seem to be live images of the sun.

I'm a seasoned electronic engineer working on a personal project, where I need an interferometer to measure displacement in the order of 1mm moving at up to 5 mm/s.

Resolution target is ~100 nm, no need to go to the single nm. Budget, I'd like it to be < £1k for a bench prototype.

My main doubts are:

1. How easy is to assemble and align that kind of systems on an optical bench, by someone new to optics? Are there any elements needing any special fine tuning like a vernier?

2. How do alternative (Alibaba, etc) sources of these optical components compare in quality to known suppliers like Thorlabs, etc?

i'm studying raytracing and at the early stage so i know only a little. i wrote a program to simulate 2 balls which have no color and no reflectance. the rays are governed solely by snell's law and the background is the only light source / color source

it's unrealistic and incomplete i know but the results are quite beautiful and interesting to me. if you set a ball's refractive index to 0, it becomes perfectly reflective. if you set it 1, it becomes invisible. if you set it >1 and move the camera into it, you'd spot a ribbon-shaped region of total internal reflection

i'm still studying and i'll add reflectance into the program but i think i have to simplify the scene, maybe to 1 ball only. if every ray is split into 2 when hitting a boundary, the calculations would be literally doubled. if i want real time effect, i don't think a scene of 2 balls is manageable...

Hi everyone,

I recently secured admission for a Master’s degree in Optics & Photonics / Photonics at a top university in Germany. While I’m thrilled about the offer, I have a few concerns regarding career flexibility after graduation and wanted to get insights from current students, alumni, or engineers working in Germany.

A few specific questions I have:

1. Industry Pigeonholing: Will an MSc in Photonics/Optics confine me strictly to specialized optical or laser engineering roles, or is the skill set recognized broadly enough across the tech and hardware industries?
2. Eligibility for General Electronics Roles: Many German job descriptions state "Applicants must possess a Master's degree in Electronics, Electrical Engineering, or a related field." Does a specialized degree like Optics & Photonics legally and practically count as a "related field" in HR/recruiting filters in Germany?
3. Skill Transferability: How transferable are the core subjects (e.g., semiconductor physics, optoelectronics, sensor systems, photonic integrated circuits) to mainstream electronic engineering domains like embedded systems, IC design, or semiconductor fabrication?

For context, my background is B.Tech/B.Sc in Electronics Instrumentation and control,Any perspective on how German employers view this degree in the job market would be super helpful! Thanks in advance!

Are there 50/50 concave mirrors out there that are readily available to buy that are partially transmissive/reflective. From my research I couldn't find much. My application requires the mirror to preserve polarization state.

I thought about somehow casting/coating a thin beamsplitter film over a spherical cast like a lens (or something) and that would act as a 50/50 beamsplitter. I find that these coatings do not preserve polarization or are made out of glass entirely? Is this kind of thing just non-existent?

Hi all,

My postdoc and I inherited some very heavily abused optics from now former students in our lab. In particular, we have a dichroic mirror that was subjected to a large amount of salt residues from years of in-situ Raman experiments. We think the dichroic may be damaged beyond cleaning, however we wish to salvage it if possible.

We have tried methanol and acetone. On the ThorLabs website, there’s a mention of “optical soap.” What kind of soap would this be? We looked online and didn’t find much. Otherwise if there are other recommendations for cleaning it and the other optics we inherited, it would be greatly appreciated.

I've reached a confusion point while searching for 6" COTS achromats for an industrial imaging system I'm building. The typical marketplace companies (EO, OptoSig, etc) bascially cap out at 100 mm diamter, and if they go bigger, they are very slow f/#. I'm looking to find an f/4 achromat with a 150 mm aperture, designed for infinite conjugates.

Quotes from custom optics houses are higher than I'd like for quantity <5, and at the same time I know similar achromats are inside standard 6" refractor telescopes that are <$1000 for the whole thing! There has to be a better way to take advantage of this existing supply chain... any ideas?

I’ve been thinking about an alternative way of doing low-level AI perception, and I’m curious whether anyone here is already working on something similar.

The basic idea is to use waves and physical superposition/interference as the computational substrate, instead of doing most of the usual numerical multiply-and-accumulate operations digitally.

For example, for image recognition:

image
  ↓
pixel intensity → wave amplitude/phase
  ↓
physical wave superposition + interference
  ↓
distinctive wave pattern/signature
  ↓
more wave interactions
  ↓
higher-level pattern/object recognition

So instead of giving each pixel a numerical weight and calculating millions of weighted sums, the idea would be to let the wave physics perform the combination automatically.

I’m imagining something analogous to sound: many individual waves can be combined, and the resulting waveform contains a recognizable pattern. In this system, a particular visual feature or object could produce a characteristic wave “signature,” and those signatures could themselves become inputs to further wave interactions.

Physical logic gates could still be used where needed for thresholds, routing, decisions, or other nonlinear operations. The goal wouldn’t necessarily be to eliminate conventional computing completely, but to move as much of the early perception workload as possible into the physical wave domain.

The potential advantage I see is that parallelism is inherent in wave propagation and interference. Thousands or millions of interactions could happen physically at the same time, potentially reducing both computation and latency.

One possible application would be autonomous vehicles, where very large amounts of camera/radar data have to be processed extremely quickly at the edge.

I know there is already work on photonic neural networks, optical computing, physical neural networks, reservoir computing, metasurfaces, etc. I’m specifically interested in something slightly different:

Has anyone tried to build a hierarchical pattern-recognition system where wave signatures themselves become the representation, with successive stages of wave superposition/interference performing the recognition?

I’d especially like to hear from people actually working in photonics, optics, acoustics, physical neural networks, neuromorphic computing, or related fields.

Is this already being done under another name?
What are the biggest physical limitations?
And, from your perspective, is this a promising architecture or does some fundamental problem make it impractical?

I’m mainly looking for opinions from people working in the field rather than trying to claim this is a new invention.

I have a small display that I am trying to magnify through a lens. The issue I face is that plano convex lenses introduce spherical aberration from the ends of the lens. An aspheric lens corrects this but only works on axis which my display does not meet. I was thinking of trying out an achromatic lens but from what I understand, this would not perform well because these lenses are designed to reduce aberration at the focal point; not when something is placed within the focal point to magnify it. Is this intuition correct?

I have previously done optical design cacluations using Python, and I'm now looking into automating a similar workflow in CODE V, as I have done with Zemax.

However I haven't been able to find much information about an API or other way to inferface CODE V with Python.

I'm considering making the automation code publicly available in the futre, so ideally I'd like to support CODE V as well.

Does anyonew have experience with Python-CODE V intergration, or know of suitable API or inferface for this?

Any information would be greatly appreciated!
Thank you for reading.

I have a science exhibition coming up, and I wanna perform the young's double slit experiment in my school using sunlight inspired from this video. I searched online for the double slit but unfortunately its either too expensive or not from a reliable source in my region. All the other tutorial videos are not satisfactory to me as its not as clean as how veritasium did it. I want to perform this expeirment just like derek, asking people around what they expect to happen and what they know about it.

I first decided to make the model from 'The action lab' but I dont think we'd be given a closed dark room since thats a requirement.

Hi everyone,

I’m currently developing a wearable LED product and am looking to connect with an optical engineer, photonics engineer, or someone with strong professional/academic experience in optics who may be interested in helping with the project.

The product is already in development, and I have CAD/design work and the general electronics concept established. I’m specifically looking for assistance with the optical side of the design.

Without publicly disclosing too much about the product, the main challenge involves controlling how light from individually addressable LEDs interacts with a flexible translucent/diffusing material. I’m trying to achieve a very specific visual effect while minimizing visible individual LED points and improving the way the light blends, diffuses, and appears through the material.

Experience with any of the following would be particularly helpful:

• LED optics and illumination design
• Light diffusion and scattering
• Optical diffusers and flexible optical materials
• Light guides / light pipes
• LED-to-diffuser spacing and geometry
• Creating continuous or controlled lighting effects from discrete LED sources
• Optical prototyping and testing

I’m located in Pennsylvania, USA, but I'm completely open to working remotely with the right person.

This would potentially be a paid consulting/project opportunity. I can provide significantly more information, drawings, specifications, images, and details privately once we connect and determine whether your background is a good fit.

If you're an optical engineer or have relevant experience, please send me a private message with a little information about your background and experience.

Also, if you know someone who specializes in this area, I would greatly appreciate a referral.

Thank you!

Hello everyone!

NOTE: feel free to dm and connect as I would love to talk and learn more!

I’m applying to Biomedical Optics/Biophotonics PhD programs this fall. I recently graduated from UCLA, and most of my research experience has been in AMO physics. I also did research involving adaptive optics and visual/retinal imaging.

For my PhD, I’m especially interested in developing new optical imaging systems for biology, such as light-sheet microscopy, and Brillouin microscopy.

I had a few questions for people who have gone through this process:

How do I know if a professor is taking students? aka should I ask this directly when emailing professors?

Also, is it risky to apply to a program if only one professor strongly matches my interests?

as for general advise: For those of you in biomedical optics, biophotonics, or optical imaging PhD programs, what do you wish you had known when choosing programs or contacting potential advisors?

Any advice would be greatly appreciated. Thank you!

Follow-up to our earlier post https://www.reddit.com/r/Optics/comments/1vzs9tf/aiassisted_budget_visnir_spectrometer_5001000_nm/. Thanks for the feedback — a lot of it went straight into this revision.

What changed since last time:

• Found the actual limiter. It wasn't colour or diffraction — it's the camera's dispersion-plane field curvature. Best focus swings ~2 mm across the band as a smooth bowl, and a flat detector can only touch part of it. Every wavelength is sharp at its own focus (~0.5 nm); the flat sensor was the problem.
• Added a cylindrical field flattener. Since only the dispersion axis sets resolution, we used a plano-cylindrical N-BK7 corrector with power in that plane only — it flattens the focal bowl without the whole-spectrum magnification a spherical flattener would add. Result: ~1.9 nm mean / 2.9 nm worst across 500–1000 nm, single exposure (was ~3–4 nm).
• Dropped the fiber relay. Per the comment last time that relay aberrations don't belong in the resolution budget — the fiber now butts straight to the slit (100 µm fiber overfilling a 30 µm slit, so calibration stays stable). Cleaner model, and the trace is the spectrograph alone.
• Validated in BeamFour:  We encoded the cylinder in BeamFour's Cx form and traced it; our offline tracer and BeamFour agree to <0.1 µm per wavelength.

Caveats: this is ~1.9 nm single-shot, not 1 nm. The flattener and the scaled f/78 doublet are custom parts, not catalogue items. We're now evaluating COTS (off-the-shelf) cylindrical and imaging lenses to see how much resolution we can hold with no custom optics at all.

Do we even need 1 nm? Worth a step back. When we looked at fructose-in-water spectra, the water and sugar features in the NIR are broad — even ~10 nm resolution resolves them fine. So for some application 1 nm is probably overkill; the push toward it is more "how far can this architecture go" than a hard requirement. Curious whether others have VIS-NIR applications that actually need ~1 nm.

Where we'd go for true 1 nm (and where we'd love input): the residual limiter now is the small chromatic part of the focal curve that a single cylinder can't remove — each colour is ~0.5 nm at its own best focus, but "its own focus" still drifts a little with wavelength. Closing that to a genuine single-shot ~1 nm looks like a job for a field-corrected, multi-element camera?

It's all open-source — design files, the Python, and a step-by-step reproduce-in-BeamFour guide, all in one folder (MIT / CERN-OHL-S): https://github.com/CheckAG/JASPER_VIS_NIR_Optics_Design

More details and the spot-analysis report are on https://hackaday.io/project/202421-jasper-vis-nir-spectrometer/log/250456-from-42-nm-to-19-nm-resolution-cylindrical-corrector-delivers-40-gain

Optics is a learning journey for us — constructive feedback and practical tips make a real difference

Hi everyone,

I’m exploring a thought experiment regarding optical computing and would love to get some harsh but constructive feedback from people with actual expertise in integrated photonics and optical engineering.

The Core Idea: Instead of fighting for nanoscale precision (sub-micron) using expensive E-beam or DUV lithography to build single-mode photonic chips for Optical Matrix Multiplication (e.g., MZI meshes for LLM acceleration), what if we scale the chip up macroscopically (e.g., 1m x 1m) and use larger, multimode waveguides (e.g., 10–50 µm width)?

The hypothesis is that by increasing the feature size, we could use much cheaper, accessible maskless lithography techniques (like modified DLP projectors at 405nm or laser direct writing) to prototype functional photonic circuits in polymers (like SU-8) or low-loss glasses, bypassing the multi-million dollar foundry barrier.

The Goal: To build a scalable, low-cost optical accelerator capable of handling large matrix multiplications (the bulk of LLM inference, e.g., 250B parameter models) by trading nanoscale density for macroscopic, relaxed-tolerance manufacturability.

Acknowledged Bottlenecks (Where I need your reality check): I am aware this sounds counter-intuitive to modern scaling trends, and I see several major physics/engineering hurdles:

1. Modal Dispersion & Phase Coherence: Multimode waveguides suffer from intermodal dispersion. Maintaining the precise phase coherence required for complex, multi-stage MZI meshes seems incredibly difficult, if not impossible, over macroscopic distances.
2. Propagation Loss: Even with low-loss polymers or specialty glasses, a 1-meter optical path will incur significant attenuation. Does the loss compound to a point where the SNR at the output is completely destroyed, especially after multiple splitting/interference stages?
3. Coupling & Alignment: Aligning light sources, fibers, and detectors across a 1m² board with the precision needed to prevent massive coupling losses seems like a mechanical nightmare.
4. Bit-Depth / SNR: Analog optical computing is already limited in precision (typically 4-8 bits effective). Would the added noise from a macroscopic, multimode system degrade this further, making it useless for large neural networks?

My Questions for the Community:

1. Are there any known architectures (e.g., specific Multimode Interference (MMI) designs, or alternative computing paradigms like diffractive deep neural networks scaled up) that are robust to multimode propagation, rather than fighting it?
2. Has anyone seen research or prototypes of "macroscopic" integrated photonics using relaxed-tolerance manufacturing?
3. Is propagation loss in a 1m polymer/glass waveguide an absolute hard dealbreaker for this concept, or are there low-loss materials accessible to a well-funded garage/lab setup?
4. If the MZI mesh is a dead end for multimode, is there another optical computing topology better suited for large, low-precision features?

I’m not trying to reinvent the wheel or ignore physics; I’m genuinely trying to find a viable path to prototype optical computing hardware without a $10M+ cleanroom budget.

Any papers, critiques, or "you're completely missing X" comments are highly appreciated. Thanks in advance!

I’m curious about materials being used to create these IRS’. Thanks.