Questions tagged [optics]

Optics is a branch of physics describing the behaviors and properties of light (electromagnetic waves). Questions regarding the properties of light, it's interactions with matter and the instruments used to detect and deflect (or concentrate) light should be posted here.

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58 views

Can waste heat in specific environments be collected into photons and converted to electricity?

This question is a repeat of another post on the physics board Here and here show the possibility to combine photons of lower energy to higher energy. Thinking of an application, it could be used to ...
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1answer
128 views

How can I estimate blocking window distance in an sCMOS sensor setup?

I am trying to establish an appropriate distance between a spectrograph output window and a CMOS sensor. The spectrograph creates a focused image on the CMOS sensor but I am trying to restrict the ...
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29 views

Bicycle headlights with different low beam reflector types

What makes second reflector different than first one in terms of efficiency and correct beam distribution (brighter below cut-off line, dimmer closer to the ground)?
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1answer
51 views

Differential Equation for: Locking a laser's frequency with a PI controller

I think I have a good understanding of differential equations, so I would like to first try to understand my system in terms of differential equations before transforming my system into the more ...
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1answer
120 views

What is the optical Lagrange invariant of an afocal system?

I am solving an optics exercise that requires to design a Keplerian telescope with a given magnification M (negative), a certain object size L and the restriction of not having lenses faster than F/1 (...
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2answers
79 views

What's the difference between pulsed lasers and frequency combs?

Can you please explain the difference between high-energy pulsed lasers and frequency combs?
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25 views

Constructing small Kretschmann Surface plasmon set up

I am trying to build a SPR setup at home which is based off this diagram: I wanted to try to miniaturize it and had some concerns about my strategy. So I was thinking I could buy a big prism and ...
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1answer
20 views

Passive Infrared Sensors (PIR) spectrum and reflections

I have a common PIR occupancy sensor (Lutron MS-OPS5M-WH). I am trying to get the sensor to cover an irregular-shaped room. I could expand the field-of-view of the sensor to cover the whole room by ...
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1answer
33 views

How solid state lasers work?

In solid state lasers a light source pumps the medium, which is a crystal. A crystal is excited and emits infrared light, until then everything is clear. What I want to know: after excitement, what ...
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2answers
354 views

galvo scanner + rotating off-axis mirror for beam offseting?

diagram: Assuming 1) the scanner can angle a beam anywhere on the circular off-axis mirror and 2) the off-axis mirror can be rotated as an the diagram to any angle needed, can the beam shooting ...
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0answers
21 views

Entrance pupil in an optical system

I'm challenging my optical design skills by coding a ray-tracing Python script. I know that many good packages exist out there, but I'm trying not to skips steps by building everything on my own. For ...
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0answers
13 views

Emerging beam from PPLN waveguide not behaving well through optics

We have a pump laser beam that is coming out of a single mode fiber and butt coupled into a PPLN waveguide crystal. We are capturing the beam at the output of the crystal with the focusing lens in an ...
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1answer
51 views

What does “coupling effects” mean in the context of optical systems?

What does it mean to say that there are "coupling effects" between some elements of an optical system? I've searched through the literature, but I cannot find a general explanation of what ...
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What power lasers can be used to heat fabrics to 70 degree Celsius?

For a project that I was building I wanted to heat fabrics to 70 degree Celsius using lasers. Since fabric is a very wide term for now I was looking to draw heat patterns on 100% cotton T-shirt and ...
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4answers
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Must rifle scopes have revealing reflections?

It's a movie trope that snipers are spotted because someone catches a glimpse of a reflection of the scope. It seems to me that this is a serious design flaw. I also know that a good number of scopes ...
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0answers
24 views

How to convey the image of a 14 mm object through a thiner (8 mm) pipe?

My setup and constraints are the following (see figure below): A rectangular pipe (~50 mm long, section 8 mm). The pipe has an apperture at one of its end, which is larger than 14 mm. A 2D object (a ...
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4answers
6k views

Why aren't screens round instead of rectangular?

Screens on TVs and phones et cetera are always rectangular. Why? Why are they not round? Eyes are round. The Sun, the source of almost all of our light, is round. Telescopes have round lenses and ...
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51 views

Compound Microscope recommendation

I am an engineering student. I want to get into microscopy research and bio-science. So I want to buy a fair enough compound microscope. I searched for them and there are so many variants from ...
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1answer
44 views

How is a parabolic mirror made by hand?

So, glassmakers were tasked with building parabolic mirrors for telescopes. I imagine that process is now entirely done in heavily automated factories. How does one make a mirror and then carve it ...
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1answer
22 views

Connect LED with a 0.25mm fiber optic

I want to connect an LED (940nm signal) to a 0.25mm fiber optic. I have researched some possibilities, which involves using shrink heat tube, which is unfortunatly too large or simply buy couplers. I ...
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2answers
51 views

How to make a panel of LEDs appear to be a single source infinitely far away

I have a square panel of 100 LEDs (a series of LED strips). I would like to use some sort of optics setup to make this panel emit light that looks like it's from a single source at infinity. Is this ...
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1answer
27 views

Calculate FTIR-system response functions from measurements of a calibrated black body

I need to find the response of my FTIR spectrometer. I do have a calibrated black-body source (area-emitter) which I measured at various temperatures. The system operates in inverse cm, cm-1. My ...
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19 views

Meaning of SNR in Instrument Specifications

I am evaluating the specifications of an FTIR instrument (Bruker Vertex) and came across the following statements/items: Signal-to-Noise 5 sec sample, 5 sec reference: >10,000:1 (<4.34 x 10-5 ...
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2answers
1k views

How to calculate meters per pixel for a given camera?

I am stuck on this problem for a while: I have a square-shaped camera, with: 1000 pixels on vertical side 1000 pixels on horizontal side I want to know the number of meters per pixel depending of ...
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2answers
408 views

how to implement autofocus for video projector

I have a modified pico video projector that I need to add an autofocus to. The focusing ring already has a fast stepper motor added to it. If the focus had to be done on the middle of the projection ...
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2answers
51 views

Can you focus a 300W LED to a small area?

I want to focus a 300W LED into a small area, about 5mm in diameter, much like focusing the sun's rays with a fresnel lens. I have to be like 2 meters away from the LED to focus the LED light with a ...
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0answers
26 views

Shrink a laser spot size

I have a laser where I can adjust the focal length, however it has a large spot size. I am trying to shrink that down significantly with a microscope objective, how can I go about doing that? Should ...
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0answers
15 views

How to calculate new focal plane position when adding a lens to a lens system?

I am currently struggling with some lens equations. I hope this is the right place to ask such questions. What I'm trying to accomplish is to add a separate single lens to a camera setup and ...
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0answers
25 views

What is a common polarizing 50/50 beam splitter cube coating

I am having problems locating references of the typical thickness and material of the coating along the hypotenuse side of 50/50 polarizing beam splitter cube. Does anyone know what these coatings ...
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1answer
31 views

What is the theory behind imaging a precision pinhole?

In my efforts to characterise a 0.67 NA microscope objective (working distance of about 15mm, effective focal length of 25mm), I have placed a 20 micron precision pinhole at the focal plane of the ...
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1answer
73 views

Relations/Equations to do with light diffusing materials

I recently started as designer at a making custom signage (small signs viewed up close, so there are lots of sizing limitations) and none of the other designers have any solid rules to rely on for ...
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1answer
262 views

Design of Compound Elliptical Concentrator and Compound Parabolic Concentrator

What is the process in design a Compound Elliptical Concentrator and Compound Parabolic Concentrator if I wanted to achieve 100% optimal concentration ? Let's assume random numbers of: A light source ...
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2answers
47 views

Electron micrographs, is it showing electrical charges?

Are electron photographs showing electrical charges? Do electrically charged parts show up more (darker in the photo) ?
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1answer
58 views

What lens is needed for a retina scan?

I was originally planning to as this on Physics Stack exchange, but found this question while searching, which directed the asker to here. While my question is not a duplicate of that, it still falls ...
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0answers
16 views

Gradient of refractive index at very short distances

I have only taken standard (basic) level math courses in high school and had learned only the fundamentals of wave and ray optics in physics classes. Therefore, Im asking only for a very general ...
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1answer
28 views

How to adjust magnification when mounting camera on microscope

I apologize in advance if this is the wrong site for this question. If this is the wrong site, would some kind soul point me towards the correct site? I have a couple of Vision Engineering TS4 ...
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2answers
33 views

What attributes of a surface are relevant to light sensors? [closed]

I'm doing a study on surfaces and I would like to describe all of the surfaces that I expect to encounter in the field and determine which ones will be the most difficult to detect. To do this, I need ...
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2answers
184 views

How to construct a compact linear Fresnel reflector

I have recently come across the concept of CLFRs, and I want to build one myself, as a private experiment. I have a rudimentary knowledge of optics (which I'm sure I'll have to refresh on) - any ...
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2answers
74 views

Would connecting 100's of small telescopes into one huge telescope make for a significantly better telescope?

Not sure if this is a Physics related or Engineering related question, but imagine that we would take 100's of small hobby telescopes and somehow managed to point them all at the same point in the sky ...
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1answer
138 views

rotating mirror system for shifting a beam?

I am looking for some mirror setup where rotation one or more elements in the mirror setup will allow to shift the beam along its axis. Two mirrors in a galvanometer scanner type setup work well for ...
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1answer
56 views

Are DVD laser diodes single transverse mode?

I am looking for a cheap source of low power single transverse mode laser diode in order to focus them to a very small point. I thought I would get that from a DVD drive but the pattern I see at the ...
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1answer
67 views

Can I use an optical fiber to direct a laser cutter? [closed]

Specifically, a 100W CO2 laser. Are there any considerations other than the maximum power for a fiber?
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0answers
87 views

how do tilt-shift DSLR lenses and video projector lens shift lenses work?

For photography there are tilt-shift lenses. For video projectors there is lens shift lenses. With video projector lens shift I get perfect, undistorted video projected up to 100% above, below, left ...
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3answers
745 views

How can I build a micrometer diameter laser beam from a common laser diode?

In order to build a lighting system for a microscope (with a digital camera) I want to make a very small diameter laser beam (parallel, rather than convergent). If possible around 1 um diameter. How ...
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0answers
34 views

What optics system can create an image both smaller and further away from the system than the source object?

My system comprises of: a light source, a set of lenses, a projected image of the light source. I want the projected image to be both further away from the lenses and smaller than the source. Which is ...
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1answer
318 views

How can I detect black spots?

I am researching about ways to continuously determine black spots (size 50+ micron) in our product stream. This stream consists of imperfect spherical polymer beads (size 3 mm) of different materials (...
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0answers
22 views

Where could I find, or what is a material that could be used with 30 GHz pulsed DC current to produce 30 GHz pulses of light?

I need to produce pulses of light that turn on and off for equal intervals at 30 GHz. I know there are lasers that are capable of this frequency, so I need to know what materials they use to produce ...
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2answers
113 views

Are thermal (LWIR) lenses as capable as visible-wavelength optics?

I'm trying to figure out whether lenses for thermal (long-wave infrared, i.e., 7-14µm) cameras are inherently more expensive or less capable than the lenses for visible cameras. Production lenses ...
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32 views

Use Fiber microscope to view micron sized particles

Can I use Fiber microscope to see micron sized particles? That's mean, can Fiber microscope be used as a typical optical microscope? Generic Handheld 400x Fiber Optical Microscope Inspection
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1answer
103 views

How to digitalize a UV image (create an array of the light output at the pixel level)?

I would like to display an image onto a screen using a digital light projector and somehow record the amount of light the screen is receiving from each pixel. I have thought about using a visible ...