Questions tagged [photonics]
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13
questions
2
votes
0answers
37 views
Comparison of beam divergence between laser diode and DPSS laser
I'm currently comparing a pulsed laser diode and a pulsed DPSS laser. For the DPSS laser, the beam divergence is listed as "beam divergence (80% of total energy): $<4 \text{mr}$". The ...
1
vote
0answers
18 views
Calculate the temperature stability of wavelength demultiplexer
Hi ive been given this question:
A wavelength demultiplexer (DMUX) used in a DWDM communication system has a
channel spacing of 100 GHz. The operating pass band of each channel is 50 GHz. The
...
3
votes
1answer
67 views
What are some examples of laser-based additive manufacturing techniques?
I'm trying to research additive (or 'bottom-up') fabrication techniques that rely on lasers or other advanced photonic systems. So far, the most prevalent technique I've come across is two-photon ...
0
votes
0answers
23 views
How would measuring the number of photons on a finite number of pulses break coherence of a weak coherent laser source in COW QKD protocol
I' m trying to understand attacks on Quantum key distribution protocols. In the COW QKD protocol, pulses from Alice are passed through an asymmetric
coupler and a fraction 'T' of the photons are sent ...
7
votes
1answer
124 views
LED Lumen Calculations
I am using an LED as a point source for a school project. I have two questions in regards to the LED(s).
I know that light follows the inverse square law when measuring perceived brightness, but all ...
1
vote
1answer
108 views
Epoxy that can withstand up to 800C and is optically transparent?
I'm looking to use an epoxy in a high-temp environment like 800C, and one that is optically transparent at 450nm (not below 90% transmission). But i'm having trouble finding one. It can be made of any ...
0
votes
3answers
380 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 ...
0
votes
1answer
145 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 ...
0
votes
2answers
450 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 ...
1
vote
0answers
29 views
Illumination properties of black lights
An elderly friend of mind whose eyesight is fading recently asked me if there was a way to illuminate her new induction stove top so that the "burner rings" would be easier to see, to her it just ...
-1
votes
1answer
166 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 ...
6
votes
4answers
702 views
Can all electromagnetic spectra be focused like a laser?
Lasers have a wide range of applications, but can be very costly to produce at high power/intensity. Since light is nothing more than a narrow band of the electromagnetic spectrum, it makes me wonder ...
4
votes
1answer
689 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 ...
