Epifluorescence and Snell's Law Quiz

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What is the minimum distance at which two distinct points of a specimen can still be seen as separate entities in microscopy?

Resolution

What is Numerical Aperture (NA) in microscopy related to?

Refractive index (n) of the medium and angular aperture of the objective

Who observed the Airy disk in 1835?

George Biddell Airy

What is Abbe's diffraction limit based on?

Airy Discs Signup and view all the answers

How did Lord Rayleigh define the limit of resolution in a diffraction-limited system?

When the center of one Airy Disc is directly overlapped by the first minimum of the diffraction pattern of another Signup and view all the answers

What is the formula for resolution based on Abbe's criterion?

$r = 0.5 \lambda \cdot NA = 0.5 \lambda \cdot n \sin \alpha$ Signup and view all the answers

What is the formula for Snell's Law?

n1 sin(q1) = n2 sin(q2) Signup and view all the answers

Define the critical angle in the context of total internal reflection (TIR).

The critical angle is the angle of incidence at which the resulting angle of refraction is 90°. It is the minimum angle of incidence for TIR to occur. Signup and view all the answers

What are the requirements for total internal reflection (TIR) to occur?

Light must be in the more dense medium approaching a less dense medium, and the angle of incidence must be greater than the critical angle. Signup and view all the answers

What is the formula for the critical angle in terms of refractive indices?

sin(q_critical) = (n2/n1) Signup and view all the answers

In STED microscopy, how does the resolution improve within the 200 nm zone?

Features can be separated within the 200 nm zone. Signup and view all the answers

What is the significance of the Rayleigh criterion in microscopy?

The Rayleigh criterion defines the minimum distance at which two points can be distinguished as separate entities in an image. Signup and view all the answers

Explain the concept of numerical aperture.

Numerical aperture is a measure of a lens' ability to gather light and resolve fine details in the object being observed. It is calculated as the refractive index of the medium multiplied by the sine of the half-angle of the maximum cone of light that can enter the lens. Signup and view all the answers

What is the Airy disk in microscopy?

The Airy disk is the central spot of light surrounded by concentric rings that appears in the image of a point source of light viewed through a microscope. It is a diffraction pattern resulting from the wave nature of light passing through a circular aperture. Signup and view all the answers

Define Abbe's diffraction limit.

Abbe's diffraction limit is a fundamental limit in optical microscopy that defines the minimum distance at which two distinct points can be resolved. It is determined by the wavelength of light used and the numerical aperture of the lens system. Signup and view all the answers

What is a Diffraction pattern in microscopy?

A diffraction pattern is the pattern of constructive and destructive interference produced when light waves pass through or around an object. In microscopy, diffraction patterns can limit the ability to resolve fine details in an image. Signup and view all the answers

Explain the Rayleigh criterion in microscopy.

The Rayleigh criterion states that two point sources can be considered resolved if the peak of one Airy disk falls on the first minimum of the other Airy disk. This criterion defines the limit of resolution in optical systems. Signup and view all the answers

How does numerical aperture affect the resolution of an optical system?

Numerical aperture directly impacts the resolution of an optical system by influencing the size of the Airy disk. Higher numerical apertures result in smaller Airy disks, leading to improved resolution. Signup and view all the answers