The nature of light ,Photometry,refelction and refraction,the endoscope

An electromagnetic wave is

propagation of the oscillating electric and magnetic fields in free space and in matter

For the electromagnetic wave the oscillations of the electric and magnetic field vectors are

perpendicular to each other and to the direction of the propagation

Radiant flux is

The energy of a monochromatic radiation per unit time

Photodetectors

convert radiometric and photometric quantities into electrical signs

For non selective photodetectors

The output signal depends on the radiant flux, but does not depend on the wavelength

For selective photodetectors

the output signal depends on both the radiant flux and the wavelength

Photopic vision is when

At normal brightness, the eye sensitivity is maximum at a wavelength of 555 nm

Scotopic vision is when

at dark, the eye sensitivity is maximum at 510 nm

Luminous flux

the monochromatic radiant flux as perceived by the human eye

Luminous intensity of a light source is

The luminous flux emitted by a point source in a particular direction per unit solid angle

Absolute refraction index of a medium is

the ratio of the speed of light in free space to its speed in the medium

When at the interface between two media the light changes its direction of propagation and

remains in the same medium, that is, reflection

When the interference between the two media the light changes its direction of propagation and

passes into the other medium that is refraction

An optical fiber is

two thin concentric layers of transparent material with the inner layer being optically denser than the outer layer

Radiometry measures the …………… ,photometry measures the ………………

electromagnetic radiation …light as perceived by the human eye

The human eye responds to electromagnetic waves with the wavelength from……….to……….

380 nm to 760 nm

A medium is ………. if its index of refraction is

optically denser ……. larger

The law of reflection says that ; The incident ray, the …………. and the normal one to the reflection surface at the point of the incidence lie in the …………….

reflected ray …… same plane

For the refraction into an optically …………. the angle of refraction is ……….. than the angle of incidence

less dense medium ….. larger