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.

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  1. C

    I Huygens principle from Kirchoff Integral (sign doubt)

    Consider the Kirkoff integral theorem and the Huygens -Fresnel principle/formula (both from Wikipedia): KIT The Kirchoff integral for monochromatic wave is: $$U({\mathbf {r}})={\frac {1}{4\pi }}\int _{S'}\left[U{\frac {\partial }{\partial {\hat {{\mathbf {n}}}}}}\left({\frac...
  2. Q

    I Does Reflecting Light Through a Birefringent Crystal Compensate Walkoff?

    Hi, I am having trouble wrapping my head around a simple (I think?) question about birefringent walkoff: If the crystal is oriented at some angle such that walkoff is nonzero between e and o beams (in a nonlinear conversion process, for example), it seems to me that reflecting the light...
  3. 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...
  4. H

    I Understanding the transmission of an etalon

    Hi there, I have a question concerning the etalon (One would think that I find an answer for this in every standard physics textbook or this forum, but I actually did not): An etalon can be built from a solid block of glas (for example) with dielectric high reflectivity coatings (let's say R=99...
  5. Const@ntine

    Maximizing and Minimizing Wavelength Contributions in Radiowave Reflection

    Homework Statement The transmitter is on the left, and the receiver is on the right. The transmitter transmits radiowaves. The distance between them is d = 50.0 m & each one's height is h = 35.0 m. The receiver can receive the radiowaves directly from the transmitter, or through reflection...
  6. mishima

    Stargazing Protecting Optics (not eyes) During Solar Observing

    Hi, I don't have much experience with amateur astronomy, but I was going to try and take a few shots with my Canon EOS 20d mounted on my 6" Ritchey-Chretien astrograph this Monday. The telescope was manufactured by Orion, and was a few hundred dollars so probably not the highest quality. Since...
  7. SchroedingersLion

    A Quantum Optics - transition from pure to mixed state

    Hello guys, I am trying to understand the following experiment: 1. Prepare a 2 level atom in state |0> 2. Shine in a Pi/2 pulse --> atom goes to 1/√2 (|0>+|1>) 3. Wait time T 4. Shine in second Pi/2 pulse a) if the state is pure: atom will go to state |1>, p1=1 b) if the state is...
  8. Const@ntine

    Lens & Reflector: Final Idol (Optics)

    Homework Statement...
  9. I

    Use of a half wave plate plus polarizer to attenuate lasers?

    The combination of a half-wave plate followed by a polarizer is commonly used as a variable attenuator for polarized lasers. The idea is that the beam enters the half-wave plate, and you rotate the half-wave plate leading to a rotation of the polarization direction of the beam. As the beam is...
  10. S

    Solar Thermal Optics - Concentrated Light

    Hi, Can someone start me out with creating predictable temperatures and inputs for calculations. Here is a miniature example of the type of parabolic circulated water heating devices I have been building. My first questions would be what is the potential heating energy of the sun per cm2? And...
  11. spareine

    Sketch of the electric field of a laser beam

    I am trying to sketch the electric field E in snapshot of a linearly polarized laser beam. Is it correct that the E vectors bend from vertical to longitudinal near the cylindrical surface of the beam, and that all field lines within a half wave segment are closed loops?
  12. C

    A Question about derivatives of complex fields

    https://arxiv.org/pdf/1705.07188.pdf Equation 5 in this paper states that $$\frac{\partial F}{\partial p_i} = 2Re\left\lbrace\frac{\partial F}{\partial x}\frac{\partial x}{\partial p_i}\right\rbrace$$ Here, p_i stands for the i'th element of a vector of 'design parameters' \mathbf{p}. These...
  13. Y

    Calculating Incidence Angle for Tilted Plate and Light Source

    Homework Statement A plate is subjected to rays from a light source located 35 degrees above the horizon. The plate itself is tilted 12.5 degrees around its vertical axis reducing the exposure to the light source. Find the incidence angle between the light source and the front face of the...
  14. S

    What is the Connection Between Physics, Computer Science, and Modern Optics?

    I have a b.s. in physics and computer science from Western Washington University. Love the opportunity to be part of the conversation. Love modern optics!
  15. Q

    Creating a two lens system of tunable focal length

    Hello, I would like to reduce the beam size of a laser by a factor of 10, with the purpose of replacing a long (750 mm) lens with a more compact design. Ideally I'd make a Galilean lens pair where the ratio of the focal lengths are 10:1 to produce a small collimated beam. However, I think I...
  16. J

    Optics : How many images can be seen in inclined mirrors?

    Homework Statement Homework EquationsThe Attempt at a Solution [/B] I tried to draw a rough figure depicting the situation. Here M is the mosquito and I1, I2, I3 are its images . Mosquito can clearly see it's image I1 .Now whether it can see I2and I3 is something I am not too sure ...
  17. J

    Optics: What is the color of the object as seen from under water?

    Homework Statement Homework EquationsThe Attempt at a Solution [/B] Since wavelength of light reduces on entering water , then the wavelength of light entering the eyes of diver is less than the wavelength of green light . Out of the given options , option B) i.e blue color is the only one...
  18. J

    Optics : White light incident on water drop

    1. Homework Statement Homework EquationsThe Attempt at a Solution [/B] I know that if white light is incident on a triangular prism , then lights of different wavelengths are deviated by different amounts and dispersion occurs . But I am not sure what would happen in this case where we have a...
  19. 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?
  20. M

    Why Does Stacking Lenses Improve My Vision?

    I am not sure of the right group for my question.Medical seems like a place to start. ---- I am monocular with an advancing cataract and macular pucker. Glasses with a corrective plastic lens help me see somewhat better. A pair of tinted No IR UV shields in front of the glasses sharpens my...
  21. Const@ntine

    Diffraction Barrier-Class of Maximum?

    Homework Statement A Diffraction Barrier has 4200 openings per 1cm. A screen stands 2.00 m opposite of the Barrier. Say that for a certain class m, the maximums that correspond with two different wavelengths (589.00 nm & 589.6 nm) abstain from each other by 1.54 mm. What is the value of m...
  22. 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?
  23. Const@ntine

    Optics (Intensity of light): Which in degrees, which in rad?

    This might be a bit of a silly question, but it's been driving me nuts for a couple of hours now. Background first: I'm reading Serway's Physics for Scientists & Engineers, Vol 2 Ed.8, and I'm currently in the Optics Chapters (light and whatnot). In O3.3 (O3 is generally about light going...
  24. S

    Optics: Half Lens in the Air, Half Lens in Water.

    Homework Statement Hello everybody! One surface of a biconvex lens (n=1,5) is in the air (na=1) while the other surface is dipped in the water (nw=4/3). If the power of the lens in the air is Po=10 Dioptri, The lens power in such condition is? Homework Equations Lensmaker Equation...
  25. shihab-kol

    Optics:Plane mirror and inverted image

    So,does a plane mirror(or a group of plane mirrors) ever form an inverted i.e. upside down image ? According to my own understanding, no. But in our home work this question was asked. So, is it possible??
  26. R

    Light beam propulsion without lasers?

    We now have the capability to do laser launch. The problem is the initial cost outlay for the lasers is still prohibitive to launch a sizable payload. The estimate of the payload you can launch to Earth orbit dependent on laser power is about 1 kg per megawatt. So to launch thousand kilo...
  27. Vaibhav Sahu

    Propagation of EM Waves in metamaterials

    We have materials that have negative effective permittivity and permeability. In such materials, when the product of permittivity and permeability is negative, solving the wave equation yields a wave with a purely imaginary wave number. Does this mean complete attenuation of the wave ?
  28. Z

    Using Snell's Law for Brachistochrone Project

    Hi all, I'm after a little guidance for I do not know what is going wrong. I understand that for Johann Bernoulli's proof of the brachistochrone problem he used refraction of light and Fermat's principle of least time. I have decided to do a project on the subject, in which I am dividing up a...
  29. T

    I Derive Relativistic Beaming Equation: Learn Physics Easily

    While studying about some physics things, I came to know a term Relativistic beaming. I looked up in wiki and found a pretty decent article which gives you an equation where the real and apparent luminosity are related by a factor of (Doppler factor)^3-a where a is spectral index. But where's...
  30. C

    Is the equivalent lens of two such that f_1+f_2<h divergent?

    The focal of the lens equivalent of two thin lens at distance h is $$1/f=1/f_1+1/f_2+h/(f_1 f_2)$$ Therefore, supposing that ##f_1>0## and ##f_2>0## (both lenses are convergent), if ##f_1+f_2 <h## then the equivalent lens should be divergent. Nevertheless consider the example in picture...
  31. M

    What Are the Conditions for Treating Atomic Motion Classically?

    Hello, I need same help with the following exercise: (1a)Recall Ehrenfest’s theorem and state the conditions for classicality of the trajectory of a quantum particle. (1b) Consider an atom whose state is described by a wavepacket with variance ∆x^2 in position and ∆p^2 in momentum. The atom...
  32. M

    I Determining Appropriate Focal Length

    So I'm working on a project where we're deciding a new lens to use for our laser diode. I need to determine the appropriate focal length based on the equation: 1/ƒ = 1/μ + 1/σ where ƒ is our focal length, μ is the distance from the lens to image and σ is distance from lens to object. For the...
  33. Biniamin Piash

    Sweat on Screen, Interference or Refraction?

    When we touch the screen of a mobile or laptop we can see some colors on the sweat adhered to the screen.Which property of light can explain it? Is it for interference or for refraction?
  34. 1

    Boundary conditions of a plane wave on a conductor

    Homework Statement Consider a plane monochromatic wave incident on a flat conducting surface. The incidence angle is ##θ##. The wave is polarized perpendicular to the plane of incidence. Find the radiation pressure (time-averaged force per unit area) exerted on the surface. Homework Equations...
  35. S

    A Stereoscopic Images and Distance Between Objects

    Hello Experts, I leaned that using a sterescopic cameras (generates 2 photos) one can measure the distance to any object in the image produced by the camera. For example, if I take a picture of a lamp post using a stereoscopic method, I can determine the Distance from the camera to the lamp...
  36. S

    Ultraviolet Laser Beam Shaping With Constraints

    Homework Statement Homework Equations Lens equation 1/f = 1/d_o + 1/d_i Minimum Gaussian beam spot 2*w_0 = ((4 * lamda * F)/(pi * D)) Where: w_0 = beam waist (half beam diameter) lambda = wavelength F = focal length of lens D = diameter of incoming spot Don't forget to match units. Let...
  37. A

    What Is the Smallest Spot Diameter the Human Eye Can Detect?

    Homework Statement The resolution of the eye is ultimately limited by the pupil diameter. What is the smallest diameter spot the eye can produce on the retina if the pupil diameter is 2.59 mm? Assume light with a wavelength of λ = 550 nm. (Note: The distance from the pupil to the retina is 25.4...
  38. CCR5

    Geometric Optics and Lens Power

    Homework Statement A farsighted boy has a near point at 2.3 m and requires eyeglasses to correct his vision. Corrective lenses are available in increments in power of 0.25 diopters. The eyeglasses should have lenses of the lowest power for which the near point is no further than 25 cm. The...
  39. H

    How Does a Combined Lens and Mirror System Create Images?

    Homework Statement The object in the figure below is midway between the lens and the mirror, which are separated by a distance d = 24.9 cm. The magnitude of the mirror's radius of curvature is 20.4 cm, and the lens has a focal length of -16.5 cm. (a) Considering only the light that leaves the...
  40. Marcus95

    Biconvex Lens Floating on Mercury

    Homework Statement A thin bi-convex lens with refractive index n has spherical surfaces with equal radii of curvature r and measured focal length f. The lens floats horizontally on the surface of liquid mercury so that its lower surface effectively becomes a spherical mirror. A point object on...
  41. asteeves_

    Optics - spherical and plane mirror

    Homework Statement A convex spherical mirror with a focal length of magnitude 24.0 cm is placed 22.0 cm to the left of a plane mirror. An object 0.300 cm tall is placed midway between the surface of the plane mirror and the vertex of the spherical mirror. The spherical mirror forms multiple...
  42. L

    Classical Find the Best Undergraduate Optics Book for Graduating Seniors

    Hey does anyone have an Undergraduate Upper-Division level optics book they like? Maybe one that describes the concepts well? I am a graduating senior, last physics courses I'll take as an undergrad and our assigned book isn't well written. Appreciate any help, thanks!
  43. TLU SPS

    Optics Research: Focus Light to <5mm, Cheap Lens Solutions

    Greetings, I am a student doing research and I have a diverging LED array light source outfitted with a diffuser and I need it to focus to a beam width of smaller than 5mm in order to image a optical trapping on a CCD camera. My apparatus has about 10cm of space underneath it, so I have to be...
  44. Y

    Conceptual question on polarization

    Homework Statement You are walking down a long hallway that has many light fixtures in the ceiling and a very shiny, newly waxed floor. In the floor, you see reflections of every light fixture. Now you put on sunglasses that are polarized. Some of the reflections of the light fixtures can not...
  45. S

    Rotate only H-Pol Component of Light beam by 90 degrees

    Is there a single optical component that will do the following? Do nothing to the horizontally polarized input, but rotate the vertically polarized input by 90 degrees, so that both beams finally emerge with the same polarization? I am looking for a single element that will replace the...
  46. 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...
  47. 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...
  48. C

    Programs Optics Program or Physics Program (w/ optics concentration)

    My main goal is optics. I love it. I did an internship having to study and learn about optics and I've had my sights set on it sense then. It's also easier for me to learn. I've applied to graduate schools, but I need to know: Are there any advantages or disadvantages of going to an optics...
  49. J

    How to determine the range of sensitivity for a camera sensor?

    I am not sure if this is the best place to ask and I will change locations if need be, but I need some guidance on how to choose a proper sensor for my project. I am currently working as part of a team on a polarimetric camera for ocean imaging. The basic premise is that images, from above the...
  50. S

    I Does Relativistic Motion Impact Quantum Optical Experiments?

    If we are considering a problem involving generic photon emitters and detectors that are moving at various relativistic velocities with respect to each other, do we need to move outside of non-relativistic quantum optics? I'd like to stress that this question is not about any definite species...
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