What is Optical: Definition and 696 Discussions

Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behaviour of visible, ultraviolet, and infrared light. Because light is an electromagnetic wave, other forms of electromagnetic radiation such as X-rays, microwaves, and radio waves exhibit similar properties.Most optical phenomena can be accounted for by using the classical electromagnetic description of light. Complete electromagnetic descriptions of light are, however, often difficult to apply in practice. Practical optics is usually done using simplified models. The most common of these, geometric optics, treats light as a collection of rays that travel in straight lines and bend when they pass through or reflect from surfaces. Physical optics is a more comprehensive model of light, which includes wave effects such as diffraction and interference that cannot be accounted for in geometric optics. Historically, the ray-based model of light was developed first, followed by the wave model of light. Progress in electromagnetic theory in the 19th century led to the discovery that light waves were in fact electromagnetic radiation.
Some phenomena depend on the fact that light has both wave-like and particle-like properties. Explanation of these effects requires quantum mechanics. When considering light's particle-like properties, the light is modelled as a collection of particles called "photons". Quantum optics deals with the application of quantum mechanics to optical systems.
Optical science is relevant to and studied in many related disciplines including astronomy, various engineering fields, photography, and medicine (particularly ophthalmology and optometry). Practical applications of optics are found in a variety of technologies and everyday objects, including mirrors, lenses, telescopes, microscopes, lasers, and fibre optics.

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  1. S

    I Modeling lossy optical media

    In Quantum Optics by Mark Fox, it says that a lossy medium can be modeled by a beam splitter that splits part of the input and sends it to the "loss port", while the unabsorbed energy propagates to the output. This model accounts correctly for the loss, the increased noise at the output etc. Is...
  2. Wrichik Basu

    Reason for Optical Isomerism (at electron level)

    I have been studying Optical Isomerism recently, and I have got one question, answer to which was not in the books that I have. I have understood what the phenomenon is, and that, how one can determine whether the plane of polarised light is rotated, and how to tell from the structure whether...
  3. M

    A What is the value of optical effective electron mass for tin

    What is the value of optical effective electron mass for tin metal (white tin)? What is the value of mean free path for electron of tin metal? At least give me some websites or papers where I can find it?
  4. Twigg

    I Hamiltonian for an Optical Phase Shifter?

    Hey all, I was reading Efficient Linear Optics Quantum Computation by Knill, Laflamme, and Milburn, when I came across their expression for the Hamiltonian for a phase shifter, given as ##\textbf{n}^{(\ell)} = \textbf{a}^{(\ell)\dagger} \textbf{a}^{(\ell)}##, where ##\ell## indicates the mode...
  5. DeathbyGreen

    I Finding Harmonic Relationships Between Frequencies in Experimental Data

    I'm trying to relate some different frequencies together in an experiment. Say I have 3 different frequencies, \omega_1,\omega_2, \omega_3. Omega 3 is the large envelope, and the other two must fit inside of it, and so they are integer multiples of each other. Is there some way to express...
  6. bruha

    B Optical eyepieces for star observations

    Hello, can I ask you if you have some experience with hyperion modular eyepiece adapter? I would like to know what is its main advantages compare to standard eyepiece ( as it is about ten times more expensive..) thank ou...
  7. N

    Optics - Adding magnification in an optical system

    Homework Statement I have a system like image below An object 1 (OP = Object plane) is projected onto the image plane 1 (IMP) where an eye is located, with a beam splitter (BS). This eye is also looking at some object at distance far away. I would like to magnify this image of the object at...
  8. M

    Longitudinal/transverse modes in optical cavity (resonator)

    I am learning about lasers and trying to clear up some blurry concepts in my head so I am not necessary using heavy math for description here so please bear with me. Let's take EM field in a rectangular box with walls that are perfect conductors (optical cavity). EM field distribution inside...
  9. V

    Optical geometry of smartphone camera.

    I posted the following on a phone forum and got no replies, as expected. It's a bit out-of-the-way and technical. Thought this might be a better place since the question still interests me. I'm using my phone to take photos of assembly procedures on my electronics workbench. However, the focus...
  10. F

    Understanding Optical Transformations

    What exactly is Optical Transform? Is it simply shining lights on material to see diffraction patterns? Why the word "Transform"? I can't get any definition of this in the net. Is it about performing Fourier Transform on the light and getting this displayed on the screen or does the screen...
  11. D

    How to explain the phenomenon of optical rotation of chiral?

    I am Professor of Inorganic Chemistry of the State University of Southwest of Bahia - UESB. I have a PhD from UFMG in Natural Product Chemistry. I use the polarimeter in my experiments and would like to understand what happens on a micro scale (chiral molecules) to provide the phenomenon of...
  12. Sophrosyne

    Medical Optical transparency of the human cornea and lens

    There are two optically transparent tissues in the human body: the cornea and the lens. But how they achieve this transparency is different, and both in turn appear to achieve this differently than in other optically clear materials like glass. The transmission of light through glass or other...
  13. KT KIM

    How can light propagate through Hollow optical fiber.

    Now I am studying a bit of optical fibers. And of course generally optical fiber works because of total reflection property of the light, which happens when the light from higher medium hits the lower medium material. However I recently found out that there also is a thing 'Hollow optical...
  14. I

    How to calculate attenuation for optical fiber bundle?

    Hi, If I understood it correctly, the coefficient of attenuation for a single optical fiber, is alpha = (10/L)*log(P(0)/P(L)). Assuming if I knew the properties of the optical fiber and the amount of optical fiber in the bundle, then the total attenuation for the bundle is approximately number...
  15. A

    Directing sunlight into the optical fiber

    Hello Is it possible to direct sunlight into the optical fiber by magnifying glass and a prism like the image below? if yes , what shape of prism should i use to do this? Thank you
  16. C

    Optical Tweezers and 3D Printing

    I am trying to assemble an optical tweezers setup and was thinking if it is realistic to assemble an optical tweezers setup using 3D printed parts? Also can DMD (Digital Micromirror Device) be used instead of SLM to manipulate the beam and generate multiple traps?
  17. S

    How does the optical system of a structured light 3D scanner work?

    Hello, can anyone explain me how optical system of a structured light 3d scanner like this one works? I tried to google it, but still didn't understand how it get's Z coordinate.
  18. esha

    Why can't we use opaque object in optical fibres?

    in an optical fibre the cladding used is ussually of a lesser refractive index so that total internal reflection occurs inside core. instead of using such a combination why can't we use a mirror like surface? will the use of opaque material partially absorb some amount of light?
  19. B

    Recommend a book for Optical physics

    Hello, Can someone recommend a book for Optical physics? I am keen to learn rigorously some fundamental aspects of light passing through various mediums (lens). I want to understand terms such as focus, blur, aberrations etc. -Ranga
  20. S

    Number of modes in optical fiber

    Homework Statement Can a single mode fiber become multimode if the wavelength of the light passed through it is small enough? I put a HeNe laser (633nm) through what I thought was a single mode fiber. If it's supposed to operate at 1300nm, then would a low wavelength of 633nm cause multiple...
  21. Z

    Optical Interference: LEDs & Coherence

    Hi, i have a question about the optical interference, supposing we have two LEDs which spectra are partially overlapped, can we have interferences?? is there any chance to have a partial coherence between the two lights??
  22. S

    Single-mode optical fibre output not Gaussian?

    Is there anything that would make a single mode fibre's speckle pattern not look Gaussian? I've attached two images (below) The Fibre C speckle pattern looks multimode The Fibre A speckle pattern doesn't really look convincingly like multimode or like single mode. A HeNe laser was used to...
  23. P

    Shortest possible damping time in Optical Molasses

    Homework Statement A beam of $$^{39}K$$ atoms is slowed with a Zeeman slower with laser light tuned to the $$4s^2S_{1/2} --4p^2P_{3/2}$$ transition with $$F=2, m_F=2 -> F'=3,m_{F'}=3 (\lambda =767nm)$$ Nuclear spin $$I=3/2$$. The most probably velocity the atoms escape from the oven with is...
  24. F

    Optical system with a medium different from air

    Hi all! I have an optical system made up like this: Circular led source -> smaller circular diaphragm -> circular even smaller lens -> cmos sensor at the posterior focal plane This is the in scale model: The image is optically after the focal plane, but practically it will lie on it due to...
  25. F

    A Deconvolution of the optical absorption spectra

    Hi people, i am doing the deconvolution of the optical absorption spectra of some quartz samples . The optical absorption spectra were obtained following a step annealing procedure.For the deconvolution i am using the Origin 9, so my question is.. Why in some articles i find the deconvolution...
  26. I

    Finding the optical power of a contact lens

    Homework Statement A farsighted man uses eyeglasses with a refractive power of 2.05 diopters. Wearing the glasses 0.020 m from his eyes, he is able to read books held no closer than 0.265 m from his eyes. He would like a prescription for contact lenses to serve the same purpose. What is the...
  27. J

    Optical Tweezers in the Ray Optics Regime

    Homework Statement Consider an optical tweezer operated in the ray optics regime as shown in Figure. Net reflection angle of the ray shown in Figure is θ = 10◦ (See Figure). Since more photons take the thick ray than the thin ray, a net force of F = 1 pN is exerted on the sphere toward the...
  28. N

    External focus in an optical system

    I feel a bit stuid for asking this. I have an optical system conisting of a laser source, a lens with some focal length F and aperture stop `(with some diamater D), followed by another lens (with another focal length) f and aperture stop d at some distance r from the first aperture stop D. What...
  29. H

    Using a photodiode in optical communications

    Homework Statement [/B] As part of my coursework in a sensor systems module at university I was given the question: State the most important reason why the photovoltaic (as opposed to photoconductive) mode would be the most suitable choice for a long distance fibre optic transmission system...
  30. Lord Crc

    Observation of laser pulse propagation in optical fibers

    Just wanted to share this, mainly because I really liked the videos (found in the supplementary section at the end). Moderators, feel free to move it to a more appropriate place. Observation of laser pulse propagation in optical fibers with a SPAD camera Recording processes and events that...
  31. H

    Optical System Creation: Maximizing Image Quality with First Surface Mirrors

    Hi guys, I have one question or maybe some questions about creation an optical system. I have a drawing of the system (see below) where are placed 2 right angle prisms. The aim of this is to reflect image from "A" to "B". I suppose that I will need to add some lenses to do it right without...
  32. M

    Schools Number of Atomic, molecular and optical (AMO) Physics Departments?

    I was just wondering if anyone new approximately how many AMO physics departments existed. Because I know that not every school has one. I was disappointed when I found out that my school doesn't have one. Thanks.
  33. BillTre

    Cool Optical Illusion and Our Created Reality

    I found this optical illusion today on the internet. This posting is accompanied by an explanation of how it works, that invokes lateral inhibition among neurons in the visual system. There is another version of this available on the internet where they show two versions. one version has red...
  34. T

    Atomic Recommend good optical clock/cold atom/frequency comb book?

    I need to learn more about optical clocks, frequency combs, atom trapping, atom interferometry, etc., and I'm wondering if there are good books or review papers you recommend? The papers I'm reading can be hard to understand and often assume knowledge I don't have. I'm a grad student if that...
  35. qnach

    Classical Finding the Right Optics Book: Faraday Rotator

    Which book (on optics) can I find talking about Faraday rotator?
  36. I

    How many state changes per second could optical computing do

    Using Optical Computing, what is the max amount of state changes that 1 transistor could theoretically have within 1 second? I once read that an electrical transistor could achieve 100 billion state changes per second, but I'm wondering what the number is for light, *and what it could...
  37. C

    Optical Phenomena: Key Elements & Assumptions

    What are the key elements for an optical phenomenon and what are the underlying basic assumptions? Example: the key elements of flight are lift, drag, thrust and weight/gravity. Also would you please recommend resources I could use to find other people that would be interested in this topic?
  38. L

    Optical detector sensitivity at low and medium flux

    Dear all, This is my first post and I'm not sure if it's the right place to ask so don't hesitate to advise if necessary. I would like to know if it's possible that an optical detector (the complete system including sensor and front-end electronics) has a better sensitivity at medium flux than...
  39. qnach

    Optical counterpart of duckbill check valve in fluid dynamics

    In fluid dynamics there is a duckbill check valve to prevent the reverse flow. In EM wave an antenna emmits/receive at the same efficiency. Is there anyway one can make a check valve for antenna so that it emmits more than received or vice versa...or perhaps emitts without even receive?
  40. T

    A Importance of optical period in coherent radiation

    I am reading a text on coherent radiation and not quite understanding a particular statement. To provide some background, the authors state that coherent radiation can arise from light-matter interactions even when considering lengths, ##L##, much smaller than the wavelength (i.e. ##V \sim L^3...
  41. OrangeYogi

    Critical bending radius of optical fibres

    Hello, How do I calculate the critical bending radius of a single mode optical fibre? I'm using a polyimide coated fibre with coating diameter of 155μm. The wavelength is 1550nm. Let me know if you have any questions. Thank you
  42. OrangeYogi

    Optical Bandpass filter specification

    Hello, For optical bandpass filter specification, what do they mean by 0.1nm bandpass filter? What is the equivalent bandpass frequency range of the filter? Thank you.
  43. J

    A Optical gain peak, PL peak and EL peak: are they same/different

    I need to understand if Optical-gain peak, (Photoluminescence) PL peak and the Electroluminescence (EL) peak are they same or different. If they are the same/different what the corresponding conditions? Would be easier for me if bulk GaAs is used for the explanation (comparison at same...
  44. I

    Where can i buy an ordinary optical collimator

    firstly hello to all, I'm new here and i'd like to ask admins to forgive me if i posted this thread in a wrong place - i could not find Optics section. i need a fresnel collimated UV light with adjustable focus. don't trust the ordinary lens because of optical aberration. one with a diameter of...
  45. D

    Max Power Output of 60mW: Troubleshooting Solutions

    I have multiple sources that have a max power output of 60mW, I am using a power meter that can read up to 200mW but when I connect directly to the source channel I get approximately 15mW or less. I have tried a different meter and I have tried different sources only to end up with the same...
  46. sounouhid

    Cobalt ferrites Optical constants

    Hi Every one I've been looking ,for a while, for a document that talk about the optical constants of CoFe2O4 witout any results can anyone help me finding one thank you for advance
  47. P

    Stargazing How to build an optical telescope for research?

    So, my SPS group is building an optical and a radio telescope (using a typical TV dish). The trouble is, these are merely for showing kids and sometimes for us to just see the sky. Because of their small size, we won't be able to do a lot of research. What I need is a telescope like the...
  48. J

    What is the textbook for optical waveguide theory using matrix notation?

    I remember using matrix notation in my course on optical waveguide theory many years ago. The lecturer was using a textbook which I cannot remember. I have since misplaced my course notes. I was wondering if anyone could direct me to the source textbook? The notation (Eq. 2.20) is attached...
  49. P

    Maximum angle of acceptance - optical fibre

    Hi all Tearing my hair out trying to calculate the Maximum acceptance angle for a problem. Experiment involved shining a laser into a tube of water. I have calculated the angle of refraction based on the average of two critical angles (one known and one measured manually) as 52.49 degrees...
  50. L

    What´s the optical effect happening in this picture?

    Hi, I was watching a tv show and I found an optical phenomenon that puzzled me. I´d say it´s related with the bokeh produced in the out of focus range, but I still can´t figure it out. I guess what makes it so weird is that the effect happens in relation with an object in the foreground (infront...
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