Optics Definition and 999 Threads

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.

View More On Wikipedia.org
Recent contents Top users
  1. B

    Relationship between interference and arm length in MZI

    A question about the Mach-Zehnder interferometer. My understanding is: If its two arms are equally long, there is destructive interference in one output and constructive interference in the other output. So, the intensity of light detected at the first output should be 0% and at the second...
  2. lbwet

    Calculate Height of Light Pole from Shadow Length

    Homework Statement At the outside, there is a vertical stick with a length of 1.1 meter and its shadow on the surface of an Earth is 1.3 meter, there also is light pole and its shadow length is 5.2 meters, what is the height of that light pole? Homework Equations Trigonometry equations to...
  3. PumpkinCougar95

    B Young's Double slit experiment with different slit sizes

    What would happen if a youngs double slit experiment is done with different slit sizes? I get the feeling that the intensity might never be zero as the waves might never cancel out completely. Am I right? How should I analyse the Intensity? Would I have to do something like what is done while...
  4. R

    Optics question: I need parallel illumination for a Contact Image Sensor (CIS)

    I am experimenting with a CIS from a document scanner (basically a row of photo sensors). I want to detect the position of an object as it passes the scanner bar. Initially in one dimension - x along the CIS. If the object is always a set distance from the light bar, I can provide illumination...
  5. C

    Condition for circular-wire polarizer to transmit no light

    I want to make a wire grid surface that transmits no light. For that I wanted to use quarter-circular arc wires. My question is what dimensions would I need to apply to the wires, would an arc with radius = wavelength of incident light be sufficient (since then it is the size of a wavelength in...
  6. Phil123

    [LENS] Given focal length and height, find object distance

    Homework Statement An object is in front of a convex mirror. We then obtain an erect image whose height is equal to 25% of the height of the object. What is the distance between the object and the mirror if we know that the focal distance is equal to 0.2m? Homework Equations M = Yi/Yo = q/p...
  7. C

    Where do antireflective coatings reflect light?

    Lets consider an index matching antireflective coating on a conducting substrate (i.e. salisbury screen). The waves reflected destructively interfere in the direction of specular reflection. However, the energy has to be conserved, and since it is not transmitted, it most me reflected in a...
  8. T

    Wave Physics - Optics - Effective Focal Length

    So we have the focal lengths: f1, f2, ..., f7 = 25mm And the distance between the lenses: d1-2, d2-3, ..., d6-7 = 50mm I have figured out that if the system would be afocal if it had an even number of these lenses. This is because the focal length of two adjacent lenses is the same as the...
  9. C

    Does a Single Metal Stripe Reflect Polarized Light at the Angle of Incidence?

    I know that only light with polarization in the plane of the "stripe" gets reflected. What i need to know is if a single metal stripe could reflect such polarised light at ONLY the angle equal to the angle of incidence or do only a whole array of stripes produce specular reflections? Sources...
  10. M

    How does the sign convention work in ray optics?

    Homework Statement I needed help to undestand some concepts in Ray Optics for my assignment. The topics which U am concerned are: Part 1: Mirror Equation, Refraction at singly curved surface, lens maker's equation, combination of thin lenses in contact. Part 2: Magnification Power of simple...
  11. HastiM

    Is it possible to create a magnetic field which can be seen?

    Hello, I am wondering if one can create a magnetic field which can be seen by a human eye? I have learned that light is nothing else but electromagnetic field with a wavelength between 400-800 nm. Colours correspond to different wavelength within the above spectrum. So isn't it theoretically...
  12. G

    A Fiber Optics Bandwidth Question

    Hi everyone :] This is my first time here. I have this Quantum Optics question (though I don't believe there is anything QM about this question, so please let me know if I've incorrectly placed this thread) as part of a (nonmarked) assignment. Here's the question: "What is the maximal...
  13. C

    Optics: Focusing Explained with an Owl

    I've made a drawing of what is confusing me here. 1. This should be a case of focusing into infinity or not? 2. Can anyone explain what happens with the owl?
  14. A

    Optics: How would you determine wavelength?

    If there is an light source that is emitting light with the wl of 450nm (blue) and it illuminated a low reflective red object. How would the wavelength be different then if the object was a white object or the emitted light is from a white led. How would we determine this. I am working on a...
  15. Pushoam

    How Is the Dielectric Constant Determined for a Rod to Prevent Light Absorption?

    Homework Statement Homework EquationsThe Attempt at a Solution ## n_1 = \sqrt{ \epsilon _1} ## ...(1) , ## n_2 = 1 ## ...(2) ## \frac { \sin {\theta_i}}{ \sin {\theta_l} } = \frac { n_1}{n_2} = n_1 ## ...(3) ## \cos{\theta_1} = \frac { n_2}{n_1} = \frac1{ n_1} ## ...(4)...
  16. Pushoam

    Dispersion relation for a surface wave of a pool of water

    Homework Statement Homework EquationsThe Attempt at a Solution ## v = \frac { \omega } k ## ## \omega = \sqrt{ kg \tanh (k) } ##I have no idea to guess the graph. I put g = 9.8 and tried to calculate ## \omega ## for different values of k. ## \omega (0 ) = 0, \omega (30) =...
  17. Pushoam

    What is the formula for calculating fringe width in an interference pattern?

    Homework Statement Homework EquationsThe Attempt at a Solution When the system is in air ## d \sin {\theta} = n \lambda ## ...(1) When the system is in water and slit separation is 2d, ## \mu 2d \sin {\theta} = n \lambda ## ...(2) ## \tan {\theta} = \frac y D ## ...( 3)...
  18. S

    Python Help with POPPY (Physical Optics Propagation in PYthon)

    If someone has used the python program POPPY, I'd like some help. How can I set up two wavefronts entering at slightly different angles, and then see the interference pattern?
  19. Domenicus

    How to project a high power white line

    Hi I have a personal art project and I am stuck, because of very limited knowledge. I'd like to project an 1-2 meter white line from 1-3 meter distance. The projected line should be as thin as possible (3-10mm) and as powerful as possible. I created a DIY projector, but my problem is that, the...
  20. Decimal

    [Optics] Find maximum order number, Fraunhofer diffraction

    Homework Statement This problem concerns a single slit diffraction experiment where Fraunhofer diffraction is observed on an observing screen via a positive converging lens with focal distance f. The diffraction pattern has a central maximum of width dy, and the vacuum wavelength of the light...
  21. esha

    The validity of ray optics in telescopes

    the largest telescope in the world has an aperture of 10 m. According to the fresnel distance this makes ray optics valid for it, for a wavelength of lightsay 500 nm, uptil a distance of 2 * 10^7 m. I have read that after the fresnel distance, diffraction tends to dominate. But telescopes tend...
  22. Pushoam

    Refractive Index: Homework Answers

    Homework Statement Homework EquationsThe Attempt at a Solution I think that ## \frac { \sin \theta } {\sin \theta ' } = \frac { n_2} { n_1} ## I am taking the dielectric constant as 1 as the potential is 0 i.e. the medium is air.. So, ##n_1 = 1## For the 2nd medium, The dielectric...
  23. N

    Height of the image of Jupiter created by the objective lens

    Homework Statement I have the following variables: f = .93 m f(e) (eyepiece) = .0082 m distance toJupiter pj = 588 E^9 diameter of Jupiter dj = 139822 E^3 Find the height of the image of Jupiter created by the objective lens of a telescope. Homework Equations M = -q/p q = f Where M is the...
  24. Marcus95

    Fringe Visibility of Sodium Doublet in Michelson interferometer

    Homework Statement The sodium D-lines are a pair of narrow, closely spaced, approximately equal intensity spectral lines with a mean wavelength of approximately 589 nm. A Michelson interferometer is set up to study the D-lines from a sodium lamp. High contrast fringes are seen for zero...
  25. V

    The crossed ladder problem and optics mirror/lens equation

    the 1/a + 1/b = 1/c keeps cropping up all over the place like the lens/mirror formula, parallel resistors but why? All these somewhat seem related to me as some kind of harmonic average, like they're the constraints of some kind of crossed ladder problem...
  26. C

    What is the correct formula for refraction at an interface between two media?

    Hi! I have a problem understanding what happens when a plane electromagnetic wave hits a surface consisting of two medias of different optical density. My old school litterature tells me two formulas which I really don't understand where they come from. The same teacher starts by telling me...
  27. A

    Geometric optics (near point problem)

    Homework Statement A person with a near point of 100 cm , but excellent distant vision, normally wears corrective glasses. But he loses them while traveling. Fortunately, he has his old pair as a spare. If the lenses of the old pair have a power of +2.55 diopters , what is his near point...
  28. B

    B "Mysterious" beamsplitter cube

    I'm using a non-polarizing beamsplitter cube in an experiment, but it's behaving in an unexpected way. I expected that, if a laser beam enters the cube from one side, ~50% of the beam passes through the cube in the same direction, while ~50% of the beam is reflected and exits the cube at a...
  29. S

    I Why Isn't My OLED Screen Image at Infinity in My HUD Setup?

    Hi, I am trying to create an HUD display - basically create a virtual image at infinity and look at it. I have two plano-convex lenses; the distance between them is the sum of their focal lengths; my object is therefore imaged at infinity. Here is the schematics that I'm pretty much trying to...
  30. P

    Optics Lab Project Holographic Weapon Sight

    Good evening everyone. For my third year optics course we have to do a research lab that includes a lab component for a project. Our prof has suggested we look into something that interests us an design a lab around it. Personally I have always had an interest in military technology and was...
  31. L

    A General definition of interferences clarification

    I require your help to list all phenomena described as interferences in physics ( as teached nowadays ) with their citations in scholar documents if they are not well known by non-specialists. I am open to adjacent domains like information theory and mathematics. There are already light...
  32. T

    Wave optics / Snell's law of refraction

    When light from a rarer medium enters a denser medium, the wave gets refracted into the denser medium and so the wavelenght and the speed of propagation decreases ( [v][1] >[SUBv][/SUB2]) but the frequency remains the same. HOW ? [SUBv][/SUB1] / [SUBλ][/SUB1] = [SUBv][/SUB2] / [SUBλ][/SUB2]...
  33. N

    Proving Fermat's principle without calculus?

    According to me this topic must be raised and discussed how fermat did it without calculus.What problems he faced since calculus was developed afterwards by Newton leibniz. http://aapt.scitation.org/doi/10.1119/1.1514235 Moderator's edit: File substituted by link due to potential copyright...
  34. E

    Dark current and dark count in photon collection devices

    Does anyone know of a simple relation between dark current and dark count in photon collection devices?
  35. 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...
  36. J

    I Calculate object distance by using just the parallax angles

    I have a simple paper with parallel grid lines and I know the height of the observer from the ground level. Now when I snap the picture with my camera, the effect i get is what is seen in the image below. Even if the lines are parallel, the perception is that they converge in the middle. When...
  37. D

    What does object space and image space mean in optics?

    What does object space and image space mean in optics?
  38. A

    Determining Parameters of a Transverse Harmonic Wave

    1. “The profile of a transverse harmonic wave, traveling at 1.2 m s^-1 is given by y(x)=(0.02 m)sin[157 rad m^-1)x]. Determine amplitude, wavelength, frequency, angular frequency, and period. Homework Equations y(x,t)=Acos(kx-wt)[/B]The Attempt at a Solution I attempted to change it to a...
  39. G

    Are the Fresnel coefficients equal for E and B fields?

    From the Maxwell Equations we know that there are four boundary conditions for an electromagnetic wave crossing an interface between two dielectric media. For the TE polarisation state, these conditions give us that E_{i} + E_{r} = E_{t} B_{i}\,\cos\theta_{i} - B_{r}\,\cos\theta_{r} =...
  40. B

    Gaussian beam spherical mirror reflection question

    Homework Statement Gaussian beam of radius R_i and beam width w_i, The beam is reflected off a mirror with a radius of curvature R = R_i and the reflectivity of this mirror is given as rho(r) = rho_0*exp(-r^2/a^2), where r is the radial distance from the center of the mirror and a is a...
  41. K_Physics

    Relative Intensity of Various Light Sources - Lab Experiment

    Homework Statement I've linked my data table down below. My problem is the relative intensity column. From the table, the units of relative intensity are w/m/s. I'm assuming this is power/velocity, where velocity is the speed of light. However, nowhere in the lab manual did it mention the...
  42. G

    What happens to the electric field's phase upon reflection?

    I have a problem with the phase of an electric field as it is reflected by and transmitted through a dielectric interface. At the boundary between the two media, all waves must exist simultaneously and the tangential component must be equal on both sides of the interface, right? Therefore for...
  43. S

    Schools Suitable list of schools for an MS to apply for a PhD program in Optics

    Fifth Year BS-MS Student from one of the premier institutes in India CGPA: 8.1/10 GRE : 310/340 168Q 142V 4AWA TOEFL: 104/120 22R 27L 26S 29W I am applying for graduate schools in the following universities. Is the list sufficient? Any suggestion is most welcome. The list is not priority-wise...
  44. A

    Physics Condensed Matter, Materials vs. Optics, Photonics and Optoelectronics

    Hi, I'm currently in my last year of undergrad and I'm wondering about which specialization I should pursue. I'm looking for career stability, I don't mind leaving academia I'd just like to employ what I study in school in my future career. So, to my questions 1) In terms of career stability...
  45. 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...
  46. Buggsy GC

    Charity engineering project water projections

    Kia ora I'm a fist year engineering student in Christchurch NZ, and a few friend and I, are designing a simple engineering report for a water projection system for an organization called gap filler. Were currently thinking of projecting an image of music onto the river Avon so people can read...
  47. R

    Learning Radiometry, Photometry, Optics, Thermodynamics, ....

    Learning Radiometry, Photometry, Optics, Thermodynamics, Fluid Mechanics(Statics & Dynamics) with great resources. I'm looking for resources for understanding the topics above. I prefer video tutorials as opposed to books but I couldn't find any video resources on Photometry and Radiometry (I...
  48. D

    I What properties allow me to see past Earth's curvature?

    I recently was able to view a 193 foot building from 24 miles away. The base of the building is approximately 15 feet above sea level and my eye level was approximately 9 feet above sea level. I was viewing the building across a Lake. I could see a substantial amount of the building, which...
  49. N

    What are the applications of H & K sheet polaroid?

    We were given an assignment on Polaroids and I couldn't find the uses of H sheet Polaroid and K sheet Polaroid. I would really appreciate the help. Thanks!
  50. S

    Are my GRE scores acceptable for PhD in Optics?

    Hello Everyone! I am Sharvari from India, interested in quantum and non linear optics and wish to pursue PhD in this domain. I am looking forward to active discussion on the grad school discussion forum as I will be applying for grad schools this year.
Back
Top