Infrared Definition and 226 Threads

What applications (except usage in rectifying infrared nanoantennas for harvesting thermal energy) would find a diode that could rectify AC having infrared frequency? Could nanoscaled thermionic diodes be used for that?

So basically, I stumbled across this concept of radiative cooling. There are a couple of YouTubers who posted videos on this topic. What I understood, was that in passive daylight radiative cooling, one applies some kind of coating or film with high sunlight reflectance and high longwave...

I have been searching for the answer yet – as I'm here – didn't find it. The current model of climate warming says the lower parts of Earth's atmosphere don't allow the IR radiation to escape freely to the outer space because the GH gas molecules keep absorbing it virtually as soon as it's been...

I stumbled upon an old thread from 2014 about invisible IR ink and have been looking into the same thing very recently. https://www.physicsforums.com/threads/does-infrared-ink-exist.744888/ So far on my research I have found an IR ink that absorbs Infrared...

Hello everyone, I need to make measurements of a collimated infrared light source at different angles, practically to create an intensity map, all this in mW/sr. I can't find any equipment able to measure in mW/sr, while there are plenty of instruments capable to measure in mW/cm^2. As I...

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There are different ranges of IR. Are they all represented as heat? If not maybe Webb telescope can read those only so our own sun isn't as much of an obstacle? Maybe xray instead?

Can you use infrared solar panels to power a ham radio and turn infrared into radio waves to get the energy past the green house gases? Because infrared gets reflected by greenhouse gases and warms the Earth while radio waves don't. Would this help cool the Earth?

Can infrared cameras focus IR radiation as a visible light camera focuses visible light? I think IR doesn't pass through glass well? What are these germanium lens about? I don't think my Flir IR camera has a lens.

I am 74yo and love Physics. If my basic knowledge of physics is correct, light is a photon. My question is: 1. Is the reason we cannot see infrared light because the spectrum travels at a wave link our eyes cannot see? 2. Does the light from the sun have all the different waves combined, and we...

Hello! I found this circuit element below in a drawer marked "IR detectors" (which I must have written on it myself, a long time ago...although I must admit don't remember doing so #OldAge). First of all, I'm trying to figure out what, exactly, it is. My initial assumption was that it looks...

This started as an astrophotography question and morphed into a thermodynamics question & it was suggested to start a new thread in Thermodynamics. Essentially the question is how do I reconcile the behavior of particular infrared photodetectors with the 2nd Law of Thermodynamics? For example...

Summary:: Do my parabolic mirrors need to be really shiny to reflect infrared? I have 2 really old CENCO parabolic reflectors. I need to use them to demonstrate infrared light radiation by placing a heat source near one mirror, reflecting its heat to a second parabolic mirror and...

Dumb question. Is there a direct heat energy relationship between a heated object and infrared radiation? 1 to 1 relationship? Or can IR go up without there being much heat?

Hello everyone. I have reading about IR radiation, reflectivity, and emissivity of materials. Metals, in general, seem to be excellent reflectors or IR radiation (they are like infrared mirrors. That said, why do they get so hot when they are left in the sun? A metal roof cannot be touched...

Hello, I have a kinda neat idea for using infrared absorbing (700-1000nm) pigment powder. There are definitely a number of places where it can be purchased, but it's quite expensive for me. https://maxmax.com/phosphorsdyesandinks/infrared-phosphors-dyes-and-inks/ir-absorbing-pigment I'm...

I am interested in energy flux density from the Moon at Earth’s surface, specifically in infrared (albeit most of it comes in infrared anyway). Physics.SX (boyfarrell) gives an estimate 89 mW/m². I doubt it for several reasons. 400 K (as effective mean) on Moon seems to be unrealistically hot...

Hello, I have this question whether it will be possible to generate electricity by heating up a suitable metal (conductor). We know from the photoelectric effect that high energy photons (of visible light; probably with frequency closer to that of violet) can knock off the outer electrons from...

Physics noob here. I have the cheapest FLIR sensor (80x60 px sensor). It captures Longwave infrared, 8 μm to 14 μm. It has a tiny lens (probably 1mm in diameter). Trying to add a zoom ability to this sensor. I have different DSLR lens and other optical scopes. I tried holding the tiny FLIR...

Do any animals see in a spectrum other than visible light and infrared?

Hello. I am curious to know if anyone here has interest in talking about materials used for an infrared sensor and how to grow them. I have read about carbon nanotube forests and things like that. Apparently, to achieve the highest sensitivity to infrared light, the key is in the elements used...

Homework Statement:: 1. Does the increase in kinetic energy in (for example) water that results from increasing its temperature result from electron excitation (i.e. increasing electron energy levels) or simply increasing their velocity or vibration amplitude/frequency? 2. If excitation is...

I've been watching an interesting nature program on Netflix called Night On Earth. The film was all taken at night using low light and infrared cameras. I was surprised how many animals and insects see well at night. It makes me curious. Do we know how much of the infrared spectrum...

Hi I'm going to use a light based source of heating for a science experiment at my university and I'm a bit confused. Sometimes the names infrared (IR) lamp and heat lamp are used as two different thing and sometimes not but I can't find clear info about it. Is there a difference? thanks in...

Hi i am trying to find the infrared emission spectrum of Lithium Nitrite on the web but having no luck. Has the spectrum been measured? If so, can I be redirected to the resource? This for general interest and a personal project. Thanks.

I am not a physics guy I'm just a husband trying to read in bed at night without disturbing my wife. Does infrared light reading glasses exist?Scientificly, can they be made?

I eventually managed to find that a CO2 molecule can absorb about 8% of infrared energy passing through it that's radiated from Earth but its actually been incredibly hard to find a comparable figure for H2O molecules. Has anyone got a percentage figure for H2O in the form of atmospheric water...

Glasshouses warm because supposedly heat (infrared) is trapped inside. However I am looking for a description of the process. Is it by glass reflecting infrared back into the glasshouse, or is it by glass absorbing infrared, heating up itself and then warming the glass house interior by...

I need to calculate irradiance in a system shown on the image. There is an infrared LED on the left and a diffuser in front of it. I need to calculate irradiance at a certain distance after the diffuser. I think I first have to calculate irradiance at the diffuser. Then multiply it by the...

hello : i have a small question , can we use multi layer thin films to increase absorption of infrared spectrum , on certain surface , ? taking in mind that we use the same kind of thin film for each layer . is that possible ? best hagop

Hi Everyone, I'm doing research in Implanted Devices in Human Body (Sensors, Hearing Aid, Pacemaker) for my college course. I've started with FitBit that uses the PPG Principle. But I'm struggling to understand why the FitBit uses both Green and IR LED whereas the sensor at the receiving end is...

Hi! My question is: I understand that at noon-day it’s hotter because of the angle with which sun rays enter our atmosphere. But at the same time, I was wondering that the band of radiation responsible for heating things is infrared, and that at noon basically all bands of lower frequency than...

I am looking for some resources describing the following content: A light with wavelength ##\lambda## is propagating in flat spacetime. The light redshifts as its wavelength gets larger and larger. In quantum field theory, this causes an infrared divergence of the field. What I want to know...

My question is about the relative eye safety of infrared (##\lambda \gtrsim 1400 \ nm##) and ultraviolet (##\lambda \lesssim 300\ nm##) lasers. Both of these wavelengths are highly absorbed by the pre-retinal water content in the cornea, so they don't really penetrate into the retina. So one...

Hello. I want to build camera for ultraviolet photography and reflectography. I plan to use debayer'ed backlit CMOS camera with or without Wood's ZWB3 glass UV filter. But I also need to find infrared cut filter because abudant IR radiation will ruin photos. Problem is that there are plenty of...

Hello, Recently I had a problem in the analysis of a raw material called Propranolol HCl, when performing Raman identification for the specific batch the obtained spectrum does not generate signal and, consequently, identity of the material. By testing other techniques like infrared and NMR, I...

In Serway and Jewett's 'Physics for Scientists and Engineers', the authors state that "People all over the world have skin that is dark in the infrared, with emissivity about 0.900.' Similarly, in Louis A Bloomfield's 'How Things Work: Physics of Everyday Life', he states that 'Your skin is...

does anyone know what is the average angle of infrared emission is by a flat diamond surface or tha directional distrabution

hi all, This isn't simply physics but is very much related. I'm trying to make an infrared thermometer or some means of remote temperature measurements for temperatures from 0 degree C to around 400 degree C I started with looking up low cost silicon photo diodes / photo transistors e.g. on...

I am looking for calculating color temperature in the IR/Microwave scale frequencies, for room temperature, 273K, 263K, 253K, all google is showing is about visible light and about display systems.

Which infrared photons can London force bound liquids and crystals of simple particles (atoms, and homonuclear diatomic molecules) legally absorb? For comparison: diamond is bound by strong covalent bonds. The restoring forces permit vibrations about the C-C bonds at about 1000/cm. But since a...

I have a Dettol automatic soap dispenser (see fig. 1) which uses a little propellor-type pump to let out a small amount of soap when you put your hand in front of the passive IR sensor. It's been working fine until just before, when I turned the lights off in the kitchen (night time, so...

Hello Forum, I am wondering why infrared cameras can only detect radiation between 1micron to 15micron. This clearly depends on the sensor's material. Based on Wien's law, this corresponds to temperatures from -79C to 89C. Are infrared cameras only detecting within this spectral range because...

I searched for "hot mirror film" on alibaba and ebay with no luck. Only seller I found was selling such films meant for car windows. For that reason it was too thick and a bit expensive because too big. I got one but yeah, it's too thick. I figured I would find few Alibaba sellers for glasses...

I just inherited an infrared camera (https://www.flir.com/products/c2/). Other than taking entertaining thermographs (cold ice cube in a warm hand, etc.), can you recommend some clever demonstrations I could show to my fellow calc-based physics students? The best I came up with is taking a...

Hi guys I know we feel infrared light as heat but my question is that is infrared a kind of light or just heat ? Thank you

Hello, I have found references giving the equation for an ABC model for GaN-based LEDs (see: file://icnas3.cc.ic.ac.uk/lsm16/materials-10-01233.pdf), but I am not able to find any for simple GaAs infrared LEDs (LED information: https://uk.rs-online.com/web/p/ir-leds/8108247/#). Does similar...

Hi I am wondering if it is possible to see the full distance of a 600m beam from a 500lm torch with an infrared filter and infrared goggles?

1. A certain type of atom has only four energy levels, as shown in the diagram. The "spectral lines" produces by this element are all visible, except for one infrared line. The quantum jump that produces the infrared line is: (see attached file) A) state 4 to 3.B) state 4 to 1.C) state 2 to 1...

I have a work assignment where I'm supposed to calculate the transmittance of blackbody radiation through liquid n-heptane, and I have data of the heptane's absorption coefficient on the wavelength interval from 2.6 to 15 micrometers (it has significant peaks at about 3.5 ##\mu##m, 7.0 ##\mu##m...