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. mishima

    Optics Experiences for High School Honors Class - Advice Needed

    I was hoping to make a great hands on optics experience this semester for my small (9) class of 11th and 12th grade (high school) students. My own experience was a bunch of ray diagrams and I would like that to not be the only thing going on here. This course is the only physics course at our...
  2. F

    Optics, calculating image distance,.given magnification and focal length

    Homework Statement The image obtained with a converging lens is upright and 3x the length of the object. The focal length of the lens is 20cm. Calculate the object and image distances Homework Equations I have absolutely no idea how to even start this question The Attempt at a...
  3. R

    Optics (double slit experiment)

    Homework Statement I have some difficulty understanding a part of the following problem: In Young’s experiment, narrow double slits 0.20 mm apart diffract monochromatic light onto a screen 1.5 m away. The distance between the 5th minima on either side of the zeroth-order maximum is...
  4. Cthugha

    Peculiarities of photons in quantum optics

    I would like to open this new topic to continue discussions on single photons which turned up in several other topics, but were a bit out of place there. So here the discussion continues. The first two quotes were basically about coincidence counting, photon statistics and the HBT-experiment...
  5. M

    Archived Optics - magnification of a converging lens

    Optics -- magnification of a converging lens Homework Statement Dioptry of converging lens is $D=3$. What is magnification ##u##? Homework Equations The Attempt at a Solution ##\frac{1}{f}=D## - dioptry. \frac{1}{f}=\frac{1}{p}+\frac{1}{l} u=\frac{l}{p} l=up...
  6. D

    Optics Problem (Curved Mirror + Lens)

    Homework Statement A convex mirror with a focal length of -20 cm is 18 cm from a convex lens whose focal length is 6.0 cm. An object is located between them, 10 cm from the mirror and 8.0 cm from the lens. The object will produce two images, one from the light which just goes through the...
  7. phosgene

    Is Optics Necessary for Physics Majors?

    So I've just discovered that second year optics is entirely optional for physics majors (and we don't have to take it in third year, either). Since I'm mostly interested in atoms and how their interactions can explain the properties of bulk matter, is optics worth taking? It's my worst and...
  8. T

    Optics problem (myopia, glasses)

    A person with myopia is standing 50 cm in front of a mirror with glasses on (-1.75 dpt). Will he be able to see himself clearly? 1/f = 1/v + 1/b I get that b = 26 cm. However my teacher says it should be 100. Is this correct?
  9. mikeanndy

    Wanna make a project for Optics Fair, Need Hepl

    I want to make a project for Optics Fair.It is an undergraduate level optics fair. Please give me some idea, if you do it will be very helpful for me.
  10. D

    Reflecting telescope optics problem-Angle on the sky to angle on a mirror

    Homework Statement When viewed from Earth, the Moon subtends an angle of 0.5° in the sky. How large an image of the Moon will be formed by the 3.6 m diameter mirror of the Canada-France-Hawaii Telescope, which has a focal length of 8.5 m? Homework Equations 1/s + 1/s' = 1/f, but I'm...
  11. P

    What are some amazing discoveries made in the field of optics?

    Hi, could you please introduce me anythings that's related to optics items function in life? books,magazins,movies anything... even good pictures for understanding...(I mean for example you tell me type this ''''' in google and find those pictures for example) if no books or ect, but you...
  12. W

    Find the object location with ray optics

    Homework Statement A 1.0-cm-tall object is placed 4.0cm from a diverging lens of focal length 6.0cm. Using both ray tracing and the thin lens formula, find the location and orientation of the image. Homework Equations -1/f = 1/so + 1/si m = -si/so = hi/ho The Attempt at a Solution...
  13. L

    Learn how to solve optics questions with 5 degree ray angles | Homework Help

    Homework Statement An object is 1.2m below the surface of a pool. By using a ray that leaves the object at 5 degrees to the normal, find the apparent depth of the object. Assume the image is located on the normal Homework Equations 1/p+1/q=1/f n1sintheta=n2sintheta2 The Attempt...
  14. M

    A strange optics (or math) problem

    Hello everyone, I was reading a physics book and found an exercise. This time I faced with a really strange one! I can't find out what I am doing wrong! I am really good at physics and math, but sometimes I fail as many people do... :smile: The answer in the book says ~0.4m, but I am unable to...
  15. L

    What is the Speed of the Image in Optics?

    Homework Statement An object is placed 20cm from a converging lens of focal length 5cm. If the object moves towards the lens at a speed of 12cm/s, at what speed does the image move away from the lens? Homework Equations 1/f=1/di+1/do v=d/t The Attempt at a Solution Let's say the...
  16. T

    Optics vs. Number Theory: Choosing My Classes for the Upcoming Semester

    I am about to choose my classes for my up and coming semester and was debating between taking Optics or Number Theory. I know they are very different courses but for those of you who have had one or both which one would you say "in general" is the more interesting course?
  17. AntSC

    Optics Problem - Maximum Dipole Emission

    I am stuck with considering a problem. I don't even really know where to start so any pointers would be a great help. I am considering a semi-analytic model for some data i have. The situation is looking at how light propogates from a point source in diamond to air. At the surface of the...
  18. B

    What kind of optics are these?

    I got these for a couple dollars at an electronics flea market. They look like maybe some kind of dichroic lens, but I don't know. Can anyone help identify them? Did I get a good deal for a couple bucks? Here's the first one. It's hard to tell from the picture, but it's got a slight red tint...
  19. T

    What is the equality of first and second focal lengths in Sears' Optics?

    Homework Statement In Sears' Optics, chapter 4, Sears claims that the first and second focal lengths (distance from first and second focal points to the first and second principal points, respectively) are equal, and he seems to imply that this is true in general, without proof. I am a...
  20. J

    Why only electric field is considered in Wave optics?

    While studying polarization I came to a word "Electric field vector" and not "magnetic field vector". Then after reading certain references I came to know that it is electric field which is considered in wave optics. Why is Magnetic field not considered??
  21. B

    Optics, Minimizing Reflection with Refraction Index Numbers HELP?

    Homework Statement What is the minimum thickness of coating which should be placed on a lens in order to minimize reflection of 401 nm light? The index of refraction of the coating material is 1.31 and the index of the glass is 1.56. Homework Equations I haven't been able to attempt the...
  22. M

    Optics, the resulting power of the lens .?

    optics, the resulting power of the lens...?? a thin lens , made of refractive index 1.5,has a front surface +11 d power and back surface -6d ..if this lens is submerged in a liquid of refractive index 1.6, the resulting power of the lens is... a)-1 dioptre b)+1 dioptre c)-5 dioptre...
  23. B

    Focal Points in Optics: Real-World Applications

    Hello everyone, I'm an optometry student who is currently doing Optics 1, and I have a general question about focal points. I can do the math regarding F1, F2, and the nodal ray, and I am decent at drawing the ray traces, but I would like to know more about the actual real world applications...
  24. I

    Books for tackling articles in Cavity QED and Quantum Optics

    Hi, I am a graduate student with a background more oriented in high energy physics and cosmology but switching to light and matter interaction, more specifically cavity QED and quantum optics. I need to have a working knowledge on those topics, being able to read state of the art articles and...
  25. M

    Scanners and Optics Explained: Mirrors, Lens & CCD Array

    Hello all! I am really rconfused about the optical part of a scanner head. :frown: I read that it consists of mirrors, a lens and the ccd array. But how this lens looks like? Is it like a large slice? Do really exist such lenses? How can such a lens have so good resolution and so large field...
  26. L

    Mathematics used in optics and intro to modern physics

    Hello. I am taking intro to modern physics and optics next semester, the intro to modern physics is a 300 level class and the optics course is a 500 level class, at Wayne State University. I want to come into next semester very well practiced in the math needed for those classes. Could...
  27. P

    Geometric Optics - Converging Lens

    Homework Statement A certain lens focuses light from an object 2.90m away as an image 46.9cm on the other side of the lens. 1. What type of lens is it? (Converging or Diverging?) 2. What is the focal length? 3. Is the image real or virtual? Homework Equations 1/di + 1/do = 1/f...
  28. L

    Optical DIY Telescope: Optics Guide for Using Magnifying Glasses

    Okay so I want to make a telescope at home... Im not a noob. Even if I am please just help me. I've got a couple of magnifying glasses ..pretty big .. I don't know the exact focal length... But one of them is twice the size of other... As soon as the sun comes up I'll find their focal...
  29. S

    Exploring Optics: A Visual Guide to Understanding Light and Its Properties

    Can anyone tell me a self teaching book or lecture notes on physical optics which has all the concept written in very clear and simple way with lots of example and all the related derivation done in step by step manner . As I am not so familiar with this subject but I want to start it so a good...
  30. K

    Optics question involving light waves

    I tried to solve this question. NO idea if I'm even on the right track. Homework Statement Suppose irradiation of a 100W light bubble (very small - be assumed as point source) is homogeneous in all directions. Because of low efficiency, only 2% of the electrical energy will be...
  31. H

    Optics - Angular Magnification

    Homework Statement The eyepiece of a compound microscope has a focal length of 2.50 cm and the objective has a focal length of 1.5 cm. The two lenses are separated by 17 cm. The microscope is used by a person with normal eyes (near point at 25 cm). What is the angular magnification of the...
  32. N

    Classical optics: Lambda-quarter plates

    Hi Say I have a magnetic field point in some well-known direction, and I have linearly polarized light incident in that direction. I want to convert my π-polarization to σ-polarization, so I find my lambda-quarter plate. However, how do I know whether it produce σ+ or σ-? Do they come with...
  33. G

    Path difference in Fibre Optics

    Hi, This is a question from a homework which has stumped me: Light is traveling along a fibre optic cable of refractive index 1.52, the refractive index of the cladding is 1.51 and the critical angle between the two is 82. a) what is the most direct route for light along the fibre-optic cable...
  34. I

    Optics question, can anyone confirm my answer?

    Homework Statement Two converging lenses of focal length=27cm are placed 16.5cm apart. If an object is placed 35cm in front of the first lens, where will the final image be produced? What will be the total magnification? Homework Equations 1/f=1/di+1/do do2=D-di1 M=-di/do The...
  35. M

    Should I Take Quantum Optics This Fall?

    I had a discussion with a professor and it was suggested that I take Quantum Optics this coming fall. I already have a full course load with 3 physics classes (Electrodynamics, Modern Physics (general), and math for physicists) and one required course (comparative religions). It was suggested...
  36. K

    Optics - Spectacles lens Power Estimation

    Hi, I'm Chaitanya, 4th year undergraduate student in biomedical engg. I have an idea of making a mobile phone application which measures the power of your spectacle glasses. The idea is we take an image with the phone's inbuilt camera. One of the spectacle lens will be held in front of the...
  37. Drakkith

    What Happens When You Play with a 3 Dollar Diffraction Grating?

    So I bought a 3 dollar diffraction grating and was playing around with it. Here's a few pictures I took just holding it up in front of my cell phone camera. Notice the bright lines in the spectrum that correspond to specific atomic transitions in the streetlight. The spectrum is dominated by...
  38. E

    Optics question-vacuum chamber for Ellipsometry

    I have shown a picture of our current ellipsometry setup. The sample is placed in the center. Polarized light comes in from the left barrel, reflects off the sample, and enters the barrel on the right. What I'm looking to build is a cover/chamber this that covers the sample but does not affect...
  39. E

    Optics question-Materials for vacuum chamber viewing ports

    Hi guys, I am interested in designing a chamber that is either purged with nitrogen gas or vacuum sealed that encloses a thin film sample. The method of analysis is via ellipsometry. (My knowledge of optics is extremely limited but know that ellipsometry measures some shift in polarization...
  40. Immersion

    Programing language for quantum mechanics, optics or plasma.

    Hi, I'm student of physics, i want to specialize in the areas of optics, quantum mechanics or plasma, but i want give an approach computational physics, therefore, my question is, which programing language is advisable for these areas of physics?. The options that most i read were fortran, C...
  41. B

    Optics/ the eye/ near, far-sightedness

    Hello all, I'm having trouble understanding the human eye and what the focal length has to do with where light converges. Why do we need a longer focal length to see distant objects and shorter to see near objects? Thank you
  42. J

    Optics - Finding Angular Size and Image Location

    1. 1. Homework Statement (SEE PIC given BELOW) A pencil is standing upright in front of a mirror at a distance of 20 cm from the surface. A variety of mirrors can be placed where the dotted box is located. The mirror may be either concave, flat or convex, based upon the following questions...
  43. C

    Source of optics problems and solutions?

    I am trying to teach myself optics out of the text by Sears, with some looks at Optics and Vision and a few other texts. I'm trying all the problems in Sears, and the answers to the odd problems are in the back. Unfortunately, I am getting a good fraction of the problems wrong. Sometimes it...
  44. P

    Create Stunning Optics Schemes with Our Software - Perfect for Academics

    Dear All, I am looking for a good software for drawing optics scheme(see examples below). I am wondering whether there is a software specially designed for this purpose. Whole my academic life, I was drawing optics schemes in Microsoft Word, Powerpoint and Coral Draw. Examples:
  45. cryora

    Wave Optics (Interference due to reflection)

    Homework Statement A radio-wave transmitter and a receiver, separated by a distance d = 50.0m, are both h = 35.0m above the ground. The receiver can receive signals directly from the transmitter and indirectly from signals that reflect from the ground. Assume the ground is level between the...
  46. C

    Optics, Telescope magnification, missing data?

    Homework Statement From Optics by Frances Sears, 1949, Chapter 6, Problem 11: (I've been working all the problems in the book on my own.) A crude telescope is constructed of to spectacle lenses of focal lengths 100cm and 20cm respectively. (a) Find its angular magnification. (b) Find the...
  47. K

    Phase operator in quantum optics

    I recently got interested in some aspects of quantum optics and have a basic question. There is an uncertainty relation concerning the phase and the particle number of a mode. How is this phase observable defined? Where can I read about such basic concepts without dwelling deeply into higher...
  48. X

    Nonstandard Concave Mirror Optics, beyond the parabola.

    Why is the parabola the most bent, concave, effective mirror? What are some properties of a third order mirror (absolute value of x^3)? There is no uniform focal point. Shouldn't shining a light beam along a normal to the x-axis reflect off of the function multiple times? Then take this to the...
  49. D

    Physics undergrad to Optics grad

    I was wondering if there was any particular difficulty in going from a Physics undergraduate program to graduate program in Optics/Photonics. Let's say to an Optics college such as the one at UCF (http://www.creol.ucf.edu/) I still have my upper level Physics classes to take so is there any...
  50. B

    Optics question - check me please?

    Homework Statement A diffraction grating is placed 0.50 m from a screen. The diffraction grating is marked 750 lines/mm. Find the distance between the second order maximum and the first order maximum when light of wavelength 550 nm is passed through the slits. Homework Equations...
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