What is Optics: Definition and 999 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. F

    MATLAB 3DES or RSA implementation for optics in MATLAB

    Can encryption algorithms like 3DES or RSA be implemented for optical networks in MATLAB? I know that the implementation of these in optics have been studied. But I am not sure what software they would have used. Can I use MATLAB for the same? Any resource on how to do this would be greatly...
  2. P

    Fish Apparent Position Using Refraction in Water

    Homework Statement A fish is 60 cm under water. A bird directly overhead looks at the fish. If the bird is 120 cm above the water level, find the apparent position of the fish as seen by the bird. The question is solved by using the principles of refraction. But, if the bird is directly...
  3. H

    Job Skills Optics Master's vs PhD: Industry Opportunities and Career Prospects Explained

    I am entering my senior year at a liberal arts college where I am earning a BA in Physics. I have some research experience in optics and by the time I graduate I will have more. I am fairly certain that I do not want to continue doing research for my career and that I am more interested in some...
  4. Tazerfish

    Are superconductors perfect reflectors?

    To my current(somewhat pathetic:wink:) knowledge the reflection off metal surfaces happens because the changing electric and magnetic fields cause "mini currents" or charge redistributions which produce their own electromagnetic waves identical to the incoming ones or in other words the...
  5. P

    Image of a virtual object by a plane mirror

    A plane mirror forms a virtual image of a real object placed in front of it and a real image of a virtual object placed in front of it. I can't picture the second case. Please show me a ray diagram showing real image formation by a plane mirror or just explain the case of real image formation by...
  6. F

    Geometrical optics question.

    Homework Statement A container with a layer of water (n=1.33) of 5 cm thick is over a block of acrylic (n=1.5) of 3 cm thick. An observer watches (perpendicularly from above) the lowest surface of the acrylic. What distance does it (the bottom surface) seems to be from the top of the water...
  7. Swepz

    What Can a Mobile Phone Camera Lens Reveal That the Naked Eye Can't?

    Hey guys I am a first timer on PF, and I am very new to the whole physics area but I am starting to find it very interesting :smile: Ive got a question about the optics of a normal camera lins of a mobile phone that perhaps someone can give me answares about of even point me in a direction...
  8. P

    Simple Optics Q: Green Filter + Blue Light = ??

    There was a question on my exam. There is a green filter and blue light is directed to the filter. Normally It should pass through the blue light but my teacher says that we wouldn't be able to see it so the color we see would be black but I think it would be blue. What is the answer?
  9. jfulky

    Internal Reflection / Fiber Optics

    Homework Statement 3. A fiber optic cable is essentially a thin fiber of plastic with n = 1.46, surrounded by a protective material with n = 1.32. The light can travel around a bend in the fiber if it can internally reflect inside the fiber. If the diameter of the fiber is d = 0.900 mm find the...
  10. G

    Proof of image formation property of spherical mirrors

    Hi. I'm trying to proof the image formation property of a concave spherical mirror. I know you can do this easily with a particular choice of rays (namely one that hits the vertex and one that passes through the center of the sphere) but I would like to show that a generic ray yields the same...
  11. K

    How can I create an adjustable liquid lens system for windows?

    Hi everyone, I am working on a project on my final project in Product design. The project is about translating digital concept into the analogue world. In my project I am especially interested in the digital “Windows” and am trying to apply the functions and possibilities of digital on to...
  12. airoll

    [Diffraction] Can a glass slide magnify an object on it?

    I have the following optical setup, in which the goal is to record the diffraction pattern of a sample on an image detector some distance away. In this particular case, the sample is sitting on a standard microscope glass slide. Now, after recording the diffraction pattern, I numerically...
  13. P

    Proving Brewster's Angle Without Fresnel Equations?

    Homework Statement Background from previous parts of the question: A simple isotropic dielectric occupies the region x>0, with vacuum in region x<0. I've found the wave equations for the electric field Incident, reflected and transmitted to prove Snell's law (Sinθ/Sinθ = c/c' = √εr) and the law...
  14. K

    Optical Is my DIY refractor telescope out of focus with the eyepiece?

    So, I recently finished my refractor telescope. I have a objective lens of 80mm and focal length of 900mm, 70mm focuser, tube length is 99.8 cm. I have a 25mm and 9mm eyepiece. I have been testing it out during the day time, on objects I can easily spot. First I use no eyepiece to focus on an...
  15. P

    Courses Math Courses For Condensed Matter Theory or Quantum Optics

    What extra math courses should an undergrad take (or self-study) if they want to go into Quantum Optics or Condensed Matter theory? I've already taken calculus, linear algebra, ODEs, PDEs, and complex analysis (I will also be doing a second course on linear algebra in two months time).
  16. Alex_Neof

    Determining the focal length of a compound lens

    Homework Statement A biconvex lens, L_1, with focal length of magnitude \left| f_1 \right| = 15 cm is used with a second biconvex lens, L_2, with focal length of magnitude \left| f_2 \right| = 25 cm to form a compound lens system. If the two lenses are placed in mutual contact what is...
  17. S

    Concave mirror: Reflected rays do not meet at one point

    I have drawn a diagram of the incident and reflected rays of an object by the concave mirror. Red color shows the incident rays, black color shows the normals drawn from the center of curvature, while green color shows the reflected rays. Shouldn't all the reflected rays meet at one point. Any...
  18. thegirl

    I Why does cos(phi1- phi 2 +kX)=cos(kx)?

    In the case of two fields interfering with each other when calculating the total electric field, cos (phi1-phi2 + kx) = cos( kx) where kx is the path difference between the two fields. How does cos (phi1-phi2 +kx)=cos(kx) Isit just algebra?
  19. T

    Triple Slit optics interferece

    Homework Statement A triple-slit experiment consists of three narrow slits, equally spaced by distance d and illuminated by light of wavelength λ. Each slit alone produces intensity I1 on the viewing screen at distance L. Consider a point on the distant viewing screen such that the path-length...
  20. M

    Over what frequency range are Maxwell's equations valid?

    Homework Statement I am studying for an Optics exam and in one of the practise tests is the following question: "Over what frequency range are Maxwell's equations valid?" Homework Equations Maxwell's Equations The Attempt at a Solution I've searched through my Griffiths Intro to...
  21. gsmtiger18

    Phase shift of light incident on 2 slits

    Homework Statement Light of wavelength λ = 450 nm is incident upon two thin slits that are separated by a distance d = 25 μm. The light hits a screen L = 2.5 m from the screen. It is observed that at a point y = 2.8 mm from the central maximum the intensity of the light is I = 55 W/m2. a)...
  22. F

    Can You Focus on Two Distances at Once?

    Homework Statement You are standing approximately 2 m away from a mirror. The mirror has water spots on its surface. True or False: It is possible for you to see the water spots and your image both in focus at the same time. Homework Equations p=object distance q=image distance The Attempt...
  23. P

    5 Questions dealing with Optics, image included

    1. A real inverted image I of an object O is formed by a certain lens (not shown); the object—image separation is d = 40.0 cm, measured along the central axis of the lens. The image is just half the size of the object, a. What kind of lens must be used to produce this image? b. How far from the...
  24. Kaan99

    Image of an Object Inside Hollow Glass Sphere

    Hello, This question is from 1990 Turkey National Physics Olympics. I tried my best to translate it clearly. 1. Homework Statement https://s23.postimg.org/cotn29afv/Hollow+Spherical+Glass.jpg The sphere of radius 2R has an empty sphere inside with radius R. In order for the image of an object...
  25. Tazerfish

    Strange Optical Phenomenon (diffraction or something else?)

    First of all i will post a picture of it ... you can find it ... somewhere sorry this is my first post :I I photographed our television with the flash on in order to recreate a strange patter i saw when looking at the suns reflection in the screen.(with my eyes it's not just the camera) You can...
  26. Vajhe

    Computational Resources for learning about Optical Beam Propagation Method (BPM)

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  27. Titan97

    Covering half of lens with an opaque coating

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  28. Alettix

    Second Law of Thermodynamics - Radiation

    Hello! This is an old problem from the Estonian-Finnish open physics olympiad (2013) and I hope you will be able to lend me some help. 1. Homework Statement Sun-rays are focused with a lens of diameter d = 10 cm and focal length f = 7 cm to a black thin plate. Behind the plate is a mirror...
  29. C

    Optics - destructive interference

    Homework Statement White light (most intense at 550nm wevelength) shines on a layer of water (n=1.33) setting on a sheet of plastic film (n=1.25). What minimum thickness of water will produce destructive interference on the surface?[/B]Homework Equations a) phase reversal of light reflecting...
  30. R

    A The Nonlinear Schrödinger Equation

    According to my textbook the nonlinear Schrödinger equation: $$\frac{\partial A(z,T)}{\partial z} = -i \frac{\beta_2}{2} \frac{\partial^2A}{\partial T^2} + i \gamma |A|^2 A \ \ (1)$$ can be cast in the form $$\frac{\partial U(z,\tau)}{\partial z} = -i \frac{sign \beta_2}{2} \frac{1}{L_D}...
  31. Peter25samaha

    Do we use optics in other branches of physics ?

    it is necessary to study the branch physics optics to use it in high energy physics , quantum mechanics and particle physics? To be more be more precise do use optics at all in these 3 ?
  32. vetgirl1990

    Phase difference between waves in two-slit model

    Homework Statement In a double slit experiment, the distance between the slits is 0.2mm and the distance to the screen is 150cm. What is the phase difference in degrees, between the waves from the two slits arriving at point P, when the angular distance of P is 10 degrees relative to the...
  33. vetgirl1990

    Finding the angle of phase difference - two slit model

    Homework Statement Light of a wavelength 548nm illuminates two slits separated by 0.25mm. At what angle would one find the phase difference between the waves from two slits to be 2 rads? Homework Equations σ / λ = ΔΦ / 2π σ: path difference λ: wavelength Δφ: phase difference The Attempt at a...
  34. vetgirl1990

    How Does Soap Bubble Thickness Affect Light Interference?

    Homework Statement (a) Calculate the minimum thickness of a soap bubble film that results in constructive interference in the reflected light if the film is illuminated with light whose wavelength in free space is λ=600nm. The index of refraction of the soap film is 1.33. (b) What is the film...
  35. Alettix

    Measurement of Focal length with Laser beam

    Homework Statement Hi! I have lately come across some tricky experimental physics tasks, where no solution is given. Some of them involved parts where the focal length of a convex lens had to be measured with a laser. How do you do this? Homework Equations 1/l + 1/d = 1/f (1) where f is the...
  36. R

    Near Point Distance of 25cm, how far should object be?

    Homework Statement A magnifier has a magnification of 9× How far from the lens should an object be held so that its image is seen at the near-point distance of 25 cm? Assume that your eye is immediately behind the lens. Express your answer to two significant figures and include the...
  37. Y

    Paid Internships in Lasers & Electro Optics

    Hi All, I am a student of Master of Technology course in Applied Physics, specializing in Lasers & Electro Optics from, India. As part of the curriculum of the course, I have to do internship in an industry or a R&D Lab working in Lasers & Electro Optics. I would be highly grateful to you all...
  38. Raptor112

    A Quantum Optics Question and Wigner Functions

    I understand that Wigner function is a quasi-probability distibution as it can take negative values, but in quantum optics I see that the Q function is mentioned as often. So what is the difference between the Q function and the Wigner Function?
  39. P

    Question regarding a two-lens system

    Homework Statement Two converging lenses, each of focal length 15 cm, are placed 20 cm apart, and an object is placed 30 cm in front of the first. Where is the final image formed and what is the magnification of the system? Homework Equations Mtot = M1 * M2 (1/f) = 1/do + 1/di The Attempt at...
  40. R

    What is the speed of sprinter running away from lens?

    Firsts of this is not my problem I don't even take physics but it is my girlfriends. She doesn't know how to get the answer an neither do I. I took some physics but not enough for this. 1. Homework Statement A sports photographer has a 160-mm-focal-length lens on his camera. The photographer...
  41. Docscientist

    Understanding the Reflection of Light: Ray Optics and Concave Mirrors

    Why a ray of light passing through the centre of curvature of a concave mirror,gets reflected along the same path?
  42. tommowg

    Using Fresnel Formulae and Poynting vector problem

    Homework Statement I'm having a problem using the fresnel formulae for these two problems below: 1. Using Fresnel formulae and expression for the Poynting vector show that at the interface between two dielectrics in the absence of absorption R+T=1, where R – is reflectivity and T –...
  43. L

    Overlaying optical field with Zernike aberration

    Hi there, optical aberrations can be expressed by Zernike polynomials Vmn(ρ,θ). Now, for my simulations i am using software that takes 4 inputs for creating aberrations onto an optical flat: m,n,R,A m,n are the Zernike orders which is perfectly clear. For R,A the manual says: R: the radius A...
  44. lonelypancreas

    Optics Enthusiast: A Freshman Engineer's Journey into the World of Light

    Hi! It's my first time to register in this site but I've been reading threads here since a long time now. I'm a freshman engineering undergraduate student whose enthusiasm for this field of science is high, especially for optics. I really enjoyed our light box activity in my high school days...
  45. F

    SONET protocol for data transmission over fiber optics

    hello forum, I have read about SONET which seems to be a physical layer protocol to transport data over fiber optics. SONET is a TDM (time division multiplexing method). TDM means that that time divided into slots and shared between different users. For example, given three users A, B and C...
  46. dquark

    Intro Physics Is There a Solution Manual Available for Nonlinear Optics by Robert W Boyd?

    I am learning nonlinear optics and recently got my hand on Nonlinear Optics by Robert W Boyd. Any other suggestions? Also is there a solution manual available for the above textbook? http://www.sciencedirect.com/science/book/9780123694706
  47. Nicholas moore

    Experts in Optics: Advice needed in working with SLDs

    I'm working on a project which will involve placing a superluminescent diode in a rocket, which will get launched in desert (obviously the SLD is just part of a greater system, the objective is not the operation of an SLD) What I need to know is if you think I could make, or where I can track...
  48. S

    Is There a Commercially Available Filter for Collimation by Filtering?

    Hello! If one were to push uncollimated light through a tube of inner radius R and length L, coated with matte black - the maximum incidence angle it will allow through would be ATAN2(R, L). On the other end of the tube, only the "most collimated" fraction of light would exit - a very small...
  49. E

    Field frequency and angle of incidence in optical waveguides

    Hello! In this previous post, most replies point out that it is not possible to predict the angle of refraction (and so the frequency) at a certain interface, given the wavelength of the original signal. In particular, But when dealing with optical waveguides, it seems to be different. I am...
  50. UchihaClan13

    Objects in Optics: Image Formation Explained

    Guys Just wanted to clarify one doubt When we consider image formation by objects We always assume there's a source of light present ,right?(because all real-point and extended objects can't always be luminous ) we also know that it's diffused reflection of light or scattering of incident light...
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