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.

Filter by
Sorted by
Tagged with
0
votes
1answer
50 views

Device that emits a safe beam of light - doesn't have to be visible (Like laser, but safer)

I am looking for a light emitting device, which can produce a narrow and accurate beam, with a small "dot" size, for a significant distance (around the 100-150 meters) similar to that of a laser, but ...
0
votes
2answers
78 views

Can we see a nanowire?

Can we see a nanowire, whose dia is say 1 nm but length is 10mm, with naked eye? To see an object does at least two out of three dimensions must be greater than the minimum size one's eye can see?
2
votes
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 ...
1
vote
0answers
2k views

Matlab code for a visible light communication system

I simulated a VLC system for an AWGN channel and plotted the BER against Ebno. I used the LED impulse response and convolved it with the signal produced to transmitting. But the results are not OK. It ...
0
votes
2answers
84 views

How might I see through a completely solid plate of steel worn as a mask?

I have a solid plate of steel I need to see through, as a mask. I need a wide FOV (at least 210 degrees). I cannot have any obstructions in the image, so no pinhole meshes or anything like that. ...
0
votes
1answer
1k views

How to see through an opaque mask?

I have a face mask that I'm planning on making, a cosplay of Wrench from Watchdogs 2. Not satisfied with existing ones, I want to go for a more realistic one. That being said, this requires that I ...
1
vote
0answers
491 views

How do LED traffic light diffusion lenses work?

In my area traffic lights with bulbs are being gradually replaced with LED traffic lights. Sometimes these lights have no diffusion lens and the individual LEDs can be seen. Other times the lights ...
2
votes
1answer
596 views

How to focus the flashlight of a smartphone?

How would I go about collimating the light from a smartphone's flashlight into a more focused beam? I'm working on a project where I need a focused beam of light to act as a light source so I can take ...
1
vote
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 ...
4
votes
2answers
674 views

Periscope camera with a mobile phone, how to make walls not visible on the camera/alternative solution?

I am trying to make like a "periscope" that i can use with a mobile camera. I have made a very quick prototype with two mirrors and it "works" but you can see the interior of the walls so it is not a ...
4
votes
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 ...
0
votes
1answer
41 views

Reusable 100um x 5mm flow chamber

I'm building a small microscope through which I need to pump fluid samples to image. Currently I'm using a flow chamber from Ibidi that is perfect (length of a standard microscope slide x 5mm x 0.1mm)...
-1
votes
1answer
164 views

Is it possible to adapt the design and principle of operation for a tunable microwave photonic notch filter to a visible light photonic notch filter?

I just read the 2015 excellent paper , "Tunable microwave photonic notch filter based on sliced broadband optical source". Is it possible to downconvert a microwave photonic notch filter to a visible ...
0
votes
1answer
69 views

How is an digital coherent receiver able to achieve 100 Mhz line-scan rate for detecting coherent light in the presence of incoherent light?

Recently, I read an October 2006 IEEE JOURNAL OF LIGHTWAVE TECHNOLOGY, article titled, High-Sensitivity Detection of Narrowband Light in a More Intense Broadband Background Using Coherence ...
1
vote
0answers
51 views

How to measure the luminance an unevenly lit object?

I need to measure luminance vs angle characteristics of an led lamp. I have access to a lux meter and a luminance meter. The problem is, that the luminance meter can only measure luminance within 1 ...
0
votes
1answer
62 views

Flatten cylindrical image using lens [closed]

I want to do something like this: but I have 3 questions that need to be answered: Is it possible to make this kind of lens? If it is possible, what are the equations/measurements needed to make it? ...
3
votes
0answers
637 views

Optics for a triangulation laser distance sensor

I'm trying to build a laser distance sensor using triangulation (With this as my main inspiration, Webcam Based DIY Laser Rangefinder). My plan is to use a linear CCD array as the imager, such as the ...
0
votes
1answer
48 views

Light transmittance of acrylic with temperature

I have a 2 mm piece of UV transparent acrylic sheet. The datasheet defines it as 80% transparent at 300 nm. However, when I use it with different temperatures (4-50°C), the transmittance ...
3
votes
0answers
173 views

3D matrix for staggering 5 ten degree wide bands of angle of incidence shifted by target wavelength and optical path difference in arithmetic series

Today, we came up with the idea of creating a 3 dimensional matrix where I simultaneously stagger 3 times 5 times 5 Fabry Perot band-reject interferometeric filters with ten degree wide bands of ...
2
votes
2answers
354 views

How does the Michelson interferometer measure the self-coherence function of coherent light in an incoherent background?

How does the Michelson interferometer measure the self-coherence function of coherent light in an incoherent background? Detection of coherent light in an incoherent background (Coutinho et al., 1999) ...
2
votes
1answer
289 views

What happens when very bright coherent light and weaker incoherent background light passes through doubly cascaded diffraction gratings?

Double diffraction is where a light beam passes through an grating with distance D1 between ridges and then passes through an grating with distance D2 The image after passing through diffraction ...
1
vote
1answer
1k views

Is it possible to reduce the divergence of a red laser pointer beam from 40 degrees to 1 degree?

I would like to find out if it is possible to reduce the divergence of a red laser pointer beam from 40 degrees to 1 degree. @Ruslan wrote on October 3 2013 that because the active zone of a ...
5
votes
2answers
1k views

Transparent, hard material that lets infrared through

I am trying to build a protective enclosure for Microsoft's Kinect v2, which emits (and perceives) IR in the 827–850 nm range. In order to fully enclose the device without blocking those signals, I ...
0
votes
1answer
107 views

What's the widest spectrum a single camera could process? [closed]

I saw this question, which was too broad, and I thought of a more specific question that can hopefully be answered. There are "normal" (visible light spectrum) cameras, infrared cameras, and UV ...
9
votes
4answers
665 views

Can cameras+display screens with window/mirror-like optical behaviour exist?

Display screens connected to cameras are significantly different from windows or mirrors. Looking through a window or mirror, we can focus on infinity, and we can move our vantage point to see a ...
1
vote
0answers
69 views

experiment with interlacing to achieve 3d effect

I am going to attempt an experiment to achieve 3d effect. I read about autostereoscopy on wikipedia. I am trying to do this, I have already processed image in that format. see the image every ...
0
votes
1answer
196 views

Is it possible to make a tunable coherent light filter with 1.8 nanometer bandwidth for visible light?

On January 1991, the esteemed Swedish professor of optics filed a patent titled "Coherence filter", that blocks coherent light regardless of laser light wavelength using destructive interference and ...
1
vote
1answer
104 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 ...
3
votes
0answers
129 views

Generating a IES file from an illuminaire and a lens

I have a IES luminaire file of a lamp and some polar candela distribution plots of lenses like: How can I create a new luminaire file combining the lamp with every lens? I could manually sample the ...
8
votes
1answer
129 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 ...
4
votes
1answer
145 views

Modifying a fixed camera lens for close focus

I found this article on hacking macro lenses. The author used a lens extension tube to allow closer focusing. IE The lens's Minimum Object Distance (MOD) was significantly reduced. I cannot find an ...
2
votes
2answers
65 views

Lens to “stretch” or enhance vertical resolution in a photo

I'm trying to measure water elevation as a function of distance in a water tank, viewed through the glass wall, as shown here: The height variations that's of interest to me is very small. Would ...
-1
votes
3answers
210 views

Would it be hard to create a camera that could see the whole electro-magnetic spectrum? [closed]

Usual cameras can capture the visible spectrum, and some others the infra-red spectrum. But the world is so much than that, isn't it? I wonder why cameras that could see a larger electro-magnetic ...
2
votes
0answers
464 views

What optics and display are used in Microsoft HoloLens?

How does Microsoft project an image so close to the eye yet understandable by the brain? How is the display transparent? This link has good information but is speculative. https://www.reddit.com/r/...
3
votes
3answers
91 views

Why is the jacket or sheath of fibre optic endoscopes always black?

Why is the jacket or sheath of fibre optic endoscopes always black? Is it just a convention, or is there a more logical explanation for this?
4
votes
1answer
5k views

Difference between continuous wave laser and a pulsed laser

I understand the difference between the two in terms of how they function; one will release all of it's energy in small pulses with the other creates a constant stream of radiation. My question is ...
4
votes
4answers
742 views

Precision measurement of liquid levels

How can I measure changes in liquid level of the order of 50 μm? The tank is cylindrical with a radius of about 12.5 mm and a total volume of about 45 ml. The fluid is water-based. The technique ...
16
votes
3answers
2k views

Why is it more reliable to use the land/pit transition in a CD-ROM?

I was reading about how CD-ROMs work and I came to this: Although it might seem simplest to use a pit to record a 0 and a land to record a 1, it is more reliable to use a pit/land or land/pit ...
6
votes
1answer
300 views

What does 'easily reversed' mean in the NIST spectral database?

I'm trying to do some processing of optical emission spectra from sputtering plasmas, and am confused by what NIST means by 'easily reversed' in their notation. Anyone have a clue?
14
votes
2answers
612 views

Why are lasers used for concentrated light applications instead of incoherent light sources?

Some laser applications consist simply of concentrating light into a small spot. Two example applications are laser welding and cutting. In these cases a CO2 laser is often used which needs a ...
4
votes
1answer
663 views

Focusing light from a laser shot into one point

I'm planning to build a laser shooting target. Something like this: In the long term I want to build something advanced like a professional grade target, in which the user is able to tell exactly ...
5
votes
1answer
127 views

How does an ultrasound device determine where the reflection is coming from?

When the ultrasound transducer emits a signal and the signal comes back to the receiver how does the software or hardware determine where it came from? I understand it finds distance or depth by delay....
1
vote
2answers
116 views

How fast can a VEX robotics light sensor operate?

In my engineering class we must make a machine that can sort 15 marbles with 3 different types in less than 2 minutes. I plan on having one marble go over/under a light sensor with a flashlight on the ...
12
votes
4answers
3k views

Will more electricity be generated by using a lens to focus sunlight onto solar cells?

I have been wondering about this question for quite some time. Assuming an ideal case, the energy from photons hitting solar cells is converted into electric energy as described by the equation: $RI^...
11
votes
1answer
1k views

How does a microbolometer (IR camera) work?

I am currently doing a project which has led me to my first encounter with IR cameras, and I am therefore quite curious as to how they operate. Specifically, I would like to know the following How is ...
3
votes
1answer
2k views

Building laser interferometer from CD/DVD drives parts

Is it possible to build interferometer, for linear displacement measurements, using old CD/DVD drive parts? I am talking about using parts such as beam-splitter, detector, laser and frame where it ...
6
votes
2answers
84 views

How to avoid dyed liquids staining reflective/transparent surfaces

I'm dealing with some hydrocarbons (diesel, gas oil, kerosene, ethanol) where I'm putting them in a chamber and shining light through them to hit a sensor on the other side in order to measure their ...
10
votes
1answer
1k views

What liquid crystals are used most frequently in displays?

Is there a specific chemical that is used frequently in the production of liquid crystal displays? During my internet research so far, it seems as if the specific chemical composition of the liquid ...
5
votes
2answers
586 views

Do contiguous laser curtains exists? and if not are there any lenses that could spread a concentrated beam into a “planar” beam

The first photo is an example of a light curtain. I am certain that every individual beam is from an individual laser and receiver pair on both cases. Would it be possible to have one laser beam ...
7
votes
4answers
7k views

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 ...