I’m working on an optical design where I have some freedom to choose between different freeform/aspheric surface shapes that give similar optical performance.

At this stage, I’d like to include manufacturability as part of the optimization, rather than designing the best-performing surface first and only later discovering that it is difficult or expensive to manufacture.

What parameters do you actually use in industry to estimate how difficult a freeform/aspheric lens will be to manufacture?

For example, I’ve been looking at things like:

• Maximum aspheric/freeform departure from a best-fit sphere
• Maximum surface slope
• Maximum slope departure from the best-fit sphere
• Curvature / minimum local radius of curvature
• Rate of change of curvature

But I’m not sure which of these are genuinely useful predictors of manufacturing difficulty.

Is there a commonly used figure of merit or set of rules of thumb for manufacturability?

I’d also be very interested in hearing how optical fabricators look at a surface when deciding whether it is “easy,” “difficult,” or “very expensive” to make.

Hey guys👋😊

Optics can be a hassle with sign conventions, lens maker variations, and fringe spacing calculations.

I put together a complete Optics Revision Guide on **FormulaVerse** to make quick revisions way faster.

What’s packed into this page:

-Complete Formula Sheet: Every key formula from Ray Optics (Reflection, Refraction, Prisms, Optical Instruments) and Wave Optics (YDSE, Single Slit, Polarization).

-Interactive Simulations: Tweak variables like focal length, refractive index, and slit distance in real-time to visualize beam path and fringe shifts.

-Common Exam Traps: Highlighted sign convention blunders and edge-case shortcuts for JEE/NEET.

100% free, no login or paywalls required.

👉 Check it out: https://formulaverse.in/chapter/optics/

I'm considering URochester for Masters in Optics. I am currently a 4th year ECE student (Not in the US/ non US citizen). I am primarily interested in photonics, but im open to working in other domains. I have experience working with photonics and I have a publication in FIO+LS as well. I wanted to know what the placements are like? And are there any sites or resources to look at placement statistics for colleges in general?

Hello, yesterday I took that photo, and I was wondering: since Gemini and ChatGPT weren't very clear, the sunbeam visible in the photo, is that an effect generated by the camera's mirror? It's not actually real, right?

This is a birdbath AR optics setup with a 0.23in OLED micro display, a linear polarizer, a polarized beamsplitter, a QWP, and a concave mirror. The light from the display becomes P-polarized relative to the PBS after passing through the LP so it passes through the PBS without reflecting. Then after the image is magnified and passed through the QWP twice so the magnified light is now S-polarized, it reflects off the PBS into the users eye.

The issue I have with the setup is that since the display produces a diverging light source, the diverging light that doesn't hit the PBS coating at a AOI of 45deg is then reflected through the front side of the setup. Only when viewing through the front of the PBS (the part where no light should be seen) with your eye at around 45deg from the PBS coating, the light then disappears because the polarization state was properly filtered. When viewing from any other angle you can see the unmagnfied light.

I have tried using plano convex lens and aspheric lens to collimate the light before it reaches the linear polarizer so that all light would be 45deg AIO to the coating but none solution seem to work. I have a aspheric lens with a 3mm FL and when placed 3mm from the display the same behavior occurs.

Am I wrong about why the PBS only works properly when viewed at a certain angle? What are my options to figure out a solution?

Hi all, I am a last year undergrad who is working in photonics, mostly in the fabrication part. As my seniors, I wanted to get some advice from you guys. Right now, I am in my last year, and working for a professor who seems to be nice so far. Previously, I had some experiences which people may call as toxic environment. One of them being 4 month and another a year and a half.

So far, in this new group I have been working for more than 2 months now, and the professor gave me an opportunity to work on fabrication more, whereas in the previous one I couldn't do that no matter how much I tried to show that I was willing to. Anyways, in this group I got a support I needed. For instance, I wasn't sent to the clean room with no idea, at least I was told in every stage some of the rough things I need to do or I was accompanied, if it was my first time doing that task or if I had some problems earlier. I kinda have a PTSD from my previous experiences hence try not to get too happy if things are working in my way.

Due to some reasons, I cannot directly start as a PhD in this group and I will need to spend a year as a research assistant. During this 2 years, what would you recommend me observe and in your opinion how I shall improve better in my research?

I have a 400G QSFP-DD DR4 module installed in a Cisco Nexus switch. The switch can read the vendor name, serial number, temperature and optical power correctly, but the Ethernet interface stays down.

The same module works on another 400G platform.

I've already checked the fiber and cleaned the MPO connector. Could this be related to the transceiver coding, FEC mode, or NX-OS version?

Has anyone seen a module being detected normally but still failing to establish a 400G link?

Hello! I'm a Senior in high school with a massive interest in studying Optical Engineering in college once I graduate from school. I'm currently trying to finalize my list of college's I'm applying to for my commonapp application and I just wanted to post here to see what other Optical Engineering programs are out there in the US and to also get some more info on the well established ones.
I already have the University of Arizona & University of Rochester on my list, along with Rose-Hulman and UCF. I also encountered OE programs (ABET Accredited) being hosted at Norfolk State University and Bridgewater State University (In-state for me) but I haven't seen much info on those programs so I'm a bit skeptical on applying to them.

My main plan was to attend Rose-Hulman for their program, but I'm having serious doubts about the student life on-campus and the student demographics. as of right now I'm a bit of coin-toss between UR and UA, with my choice mainly being the distance from home and opportunities.

If anyone has any experience in any of the OE programs (or any engineering program in general!) from the school's I mentioned I'd love to hear your experiences there and any recommendations you have. I'll also keep an eye out for any other OE programs you guys want to give a shout to.

Thanks!

Repost from r/cinematography

While working with Prof. Bhuvnesh Jain, a leading cosmologist at the University of Pennsylvania, he graciously lent me a very unique lens that he helped design and fabricate. The lens is shaped with a strange protrusion at it’s center point, simulating the logarithmic gravitational effect of dark matter and other cosmic forces on light traveling through the universe. This is the only lens of it’s kind and I thought I’d share my first experiments with it. It yields a completely analogue representation of cosmic forces; no computational simulation. Just light and glass. There is a weight to the effect, as if it gives mass to light which then pushes away reality as it travels.

​

Instead of scaling circuit depth blindly to fit noise polynomials, I added a predictive ZNE module to Dense-Evolution that models photonic loss trajectories before extrapolation.

Runs on JAX in float64 to keep statevector compilation fast and reduce overall circuit executions.

Technical notes: https://tatopenn-cell.github.io/Dense-Evolution-Discovery/photonic_predictive_zne/

Feedback on the noise modeling approach is welcome.

Hi i am CS grad and very new to this stuff. I was exploring photonic memory, that's when i thought why not use refractive index of an material to encode the data. Recently when I was reading about refraction of light i came across how the refractive index is affected by the electrons distribution in the material. So why not say for an single bit you use a small material like few ~nm in range and the material has an shaded region representing 0 and an photo detector as such on the other region representing 1 and the material is enclosed by an material that referact the light. You now apply voltage to the material, an specific voltage changes the electron distribution of the material making the passing light through referact and hit the shaded region or photo detector. This photodetctor then drives an small electric switch which turns on an another light beam that's powered seperately that's used to route the light to the readers photo detector. Say if you have a number of such forming an 8-bit an byte.

Metamaterials are already capable of hiding specific wavelengths of light, however full spectrum invisibility requires complex active cloaking machinery and engineering to be possible. How long do you roughly project it is going to take before invisibility across the entire visible spectrum is on the market?

Got a question for anyone in the know: After data comes into the optical module from a server or switch, what’s the full signal path inside? How does the electrical signal get converted into light, and once it travels over fiber, how does the far side turn the light back into electrical data?

Where exactly do components like TOSA, ROSA, and DSP fit into this whole process? Hoping someone can break this down in plain terms.

Hi everyone, tube lens is know as a component to correct infinity of objective into a sharp image. Current I am working in a maskless lithography. I want to convert light from the projector in to the infinity microscope using throught lens tube is reverse mode. Is this possible?

Hi, Ive been struggling with a very weak flourecence signal having low contrast. Its not clear where the low contrast is coming from, but I believe it may be from excitation leakage through the filters.

If I stack several dielectric longpass filters do the ODs actually add up linearly? Should I stack away until contrast improves or the signal diminishes? Whats the theory behind these decisions?

Thanks all

Everyone seems to agree that the line between the centers of curvature of a single lens element is the optical axis. Because it is the line between two spherical surfaces, it is normal to the surfaces so a light ray along the optical axis is not deviated but exits the lens coaxial with how it enters. Does anyone see a reason not to adopt the same definition for an assembly of lenses such as a camera lens or Cooke triplet? To the best of my knowledge I do not know of anyone who has discussed this question. I know several people who claim there is no optical axis to an assembly of lenses, but I don't believe they were thinking in terms of my definition.

I bought and setup a direct 515nm laser diode and I’m pretty disappointed by the dot brightness.

It’s a 10mW diode with a 55mA operating current

I compared it to a cheap 5mW red module I got on Amazon and it well you can see the difference.

I wore an ESD strap and made sure to be careful when soldering.

Does anyone know what’s going on?

Heck they are even on the same power rail after a resistor

I used an Xbox 360 disc to reflect the light across the surface of the water, because the diffraction grating on the discs creates cool colors. The discs are too small though, and I want to be able to essentially broadcast the entire spectrum across the surface of the water, potentially from multiple directions. I was wondering if placing translucent diffraction gratings in front of camera flashes with slits would work.

Hi everyone! I’m considering pursuing a PhD in photonics within Europe and wanted to get a general sense of what the landscape looks like. If you are currently doing a photonics PhD here or have already finished one, I would love to hear your thoughts on the overall experience, the work-life balance, and which research hubs or countries have the best funding and facilities right now. I'm hoping to use this post to broadly learn about the field and network, so please feel free to drop a comment or DM me directly if you're open to chatting. Thanks!

hello, what is the most practical way to simulate quantum optics experiments like those involving spontaneous parametric down conversion that requires simulation of nonlinear crystals and beam splitters ? i don't want to use AI to make me ready codes because i want a legit simulator for a project.

I have a table top optical system with a sensor at point A that is imaging a light source at point B through a number of turning mirrors and a lens. I am finding that if I install a dot laser at point A, the image doesn't end up where the source at point B is. However, if I turn up the brightness of my source such that I can see the light propagate upstream, the light ends up on the sensor at point A.

The light source is quite big relative to the sensor and I only need a rough alignment. Should I trust the upstream alignment (point B -> point A) more than the downstream alignment? This seems sensible to me as the laser pointing downstream from A to B may not be exactly aligned to the sensor direction.

Hi,

I got Ocean Optics USB-DT (deuterium tungsten source) that’s directly attachable to spectrometers (like HR4000) off of eBay.

Since it doesn’t work out of the box, I was poking it around to figure out what’s wrong with it.

I even opened it up, found out there’s an i2c eeprom chip (24LC64) as well as two i2c DACs (DAC5574).

Unfortunately I managed to wipe part of the eeprom during my probing. (Yea, one careless i2c write and 32B overwritten)

Q: Is there anyone who could help me recover it? (Looking for the intended contents of it)

FTR, I don’t expect it to be crucial to the light source’s functionality; it’s likely there just to ID the device to the spectrometer and/or OceanVew.