Photonics

WUT photonics

26 flashcards · Other · by Aida Muravyeva

1. Applications of quantum optics:

   Entanglement & quantum information processing – core field. ncorrect: • Photoelectric effect & photoconductor – classical solid-state physics. • Photochemical effect & tunneling – not specific to quantum optics. • Hydrogen lines & uncertainty principle – atomic physics, not applied quantum optics.

2. Photodetector division:

   • Photovoltaic and photoconductor – standard classification. Incorrect: • Photochemical & semiconductor – wrong grouping. • Conductor & voltaic – nonsense. • Luminescent & absorptive –

3. What determines quantum dot emission wavelength:

   Correct: • Average particle diameter – quantum confinement. • Chemical composition of particle – material bandgap. Incorrect: • Substrate composition – irrelevant. • Type of discha

4. Main quantum number:

   Correct: • n – defines energy level. Incorrect: • l – orbital shape. • m – magnetic orientation. • s – spin.

5. Order 3D tech least → most realistic:

   Aska 3D → Stereoscopy → FogScreen → Spinning screen → Pepper’s Ghost → AR → MR → Integral imaging → Light-field → Holograph

6. Pepper’s Ghost effect:

   Correct: • Pyramid requires distortion correction – geometry issue. • Cone requires distortion correction – same concern.

7. Real optical system:

   Correct: • Spherical surface perfect only paraxially – approximation. • Limited diameter → blurred image – diffraction. • Manufacturing defects deform wavefront – real-world issue. Incorrect: • Limited diameter → sharper image – smaller aperture → lower resolution.

8. Material selection (F–blue, d–yellow, C–red):

   Correct: • SF2 – dispersive prism – high dispersion. • BK7 – imaging optics – low dispersion, stable. Incorrect: • SF2 – imaging optics – too much dispersion. • BK7 – dispersive prism – not dispersive enough.

9. Chromatic dispersion:

   Correct: • Can be advantage or disadvantage – depends on use (prism vs lens). Incorrect: • Temperature dependence – that’s thermal dispersion. • Source of spherical aberration – unrelated; that’s shape-based. • Present in mirrors – mirrors don’t disperse.

10. Total internal reflection:

    Correct: • Occurs from higher n → lower n – necessary condition. • Occurs for angles > critical angle – TIR requirement. Incorrect: • Occurs from low n → high n – impossible. • Does not occur for angles > critical – wrong, it does. • Does not occur for angles < critical – correct statement but asks for false → refraction occurs instead.

11. 8. Refractive index:

    Correct: • Defined as c/v – ratio of speeds. Incorrect: • Does not depend on wavelength – it does (dispersion). • Does not depend on temperature/pressure – small dependence exists. • Does not depend on altitude – atmospheric refractive index changes with heigh

12. 7. Basic optical phenomena descriptions:

    • Refraction: change of direction when crossing media. • Reflection: bouncing off a surface. • Scattering: redirection by particles. • Absorption: photon energy taken up by material.

13. Wave optics includes:

    Correct: • Diffraction – wave bending. • Polarization – wave orientation. • Refraction – wave speed change. Incorrect: • Absorption – energy loss, not a wave-optics phenomenon.

14. Geometrical optics:

    Correct: • Study without diffraction or interference – ignores wave effects. • Objects treated as point radiators – ray approximation. Incorrect: • Study with diffraction/interference – that’s wave optics. • Describes the nature of light wave – too broad, not specific to geometrical optics.

15. Description of light radiation:

    • A – Geometrical optics –

16. Photonics employs which spectra:

    Correct: • UV – used in photolithography, sensing. • Infrared – telecom, imaging. Incorrect: • X-ray – different field of optics. • Microwaves – belong to RF engineering.

17. Photonics:

    Correct: • Science of light detection – photonics detects photons. • Science of light generation – photonics generates and manipulates light. Incorrect: • Uses only visible spectrum – photonics uses UV–IR too. • Information is carried by electron – photonics uses photons, not electrons.

18. Geometrical optics:

    Advantage: Simple concepts and analysis of rays based on basic phenomena: Refraction Reflection Problems: Ray is a geometric concept of light track without the possibility to assign it the power. It is impossible to calculate power division between reflected and passing beams. Does not explain phenomenon of interference, diffraction and polarization.

19. Law of refraction(snell's law)

    n1*sino1=n2sinO2

20. Law of reflection

    O1=-O2

21. Total internal reflection TIR

    occurs when an angle of incidence of a ray propagating from a higher index medium to lower index medium exceeds the critical angle. So: sin O= n2/n1, N1> N2!!!!!! CRITICAL ANGLE IS 90 for n2* Sin02.

22. Why will a real optical image never produce a perfect image?

    Spherical surface is perfect only in paraxial space Manufacturing defect causes wavefront deformation 3. We cannot produce such large lens, because it should be infinitely long

23. Thick lens and thin lens:

    The main difference is that a thin lens is an approximation where the lens thickness is negligible, simplifying calculations by assuming all refraction occurs at a single plane. A thick lens is a real-world lens with a significant thickness, requiring more complex calculations that account for its two principal planes and the optical distance between them.

24. Mirrors and Lenses. Advantages and disadvantages

    Mirrors reflect light, which avoids chromatic aberration and is ideal for large, high-resolution instruments, but they can be more difficult to support and can cause issues with obstructions in the light path. Lenses refract light, making them suitable for applications like eyeglasses and microscopes, but they suffer from chromatic aberration (color fringing) and can be heavy, difficult to support, and prone to flexing in large sizes

25. Glass lenses VS molded (plastic lens)

    glass gives more optical clarity and scratch resistance, has a wide range of elements on the market, while plastic is lighter, cheaper and has higher impact resistance and a possibility to create more than 2 optical surfaces or integrate with other elements

26. Prisms? What do we need them for? What are their advantages and disadvantages?

    Usually are used to change the direction of the beam or to divide the light. Disadvantages: weight, the larger the solid the bigger the chromatic aberration. Advantages: reflection, wide range, multiple variation