How do you measure light? How do you measure light faster than 100ps?
Snell's regulation: n1 sin(theta1) = n2 sin(theta2) come to a determination on your attitude of incidence: theta1 = arcsine ( sin(theta2) n2 / n1) they supply the attitude of refraction, theta2. you will possibly desire to assume that air has an index of refraction n1 = a million. you fairly might opt to seek for for the index of refraction of water, n2. Then plugnchug. just to quibble with goulden--consistently do your fixing till at last now you do your plugging. you do now not opt to be doing algebra with numbers and instruments already floating around.
What do you intend to measure? Light has several different properties: brightness (intensity), color, speed, spatial shape. All of these can be measured when the light interacts with materials. The most common method uses the CCD chip inside a digital camera. Each pixel on the chip is a stack of semiconductor layers that give off electricity when hit by light. This photoelectric effect measures the intensity of the light. The color of the light is measured by placing filters in front of the pixels and measuring the relative intensity of different colors. the spatial pattern is measured by having a grid of these pixels that measure the light's intensity and color as a function of spatial location. The phrase faster than 100ps does not make sense. Picoseconds are a measure of time, not speed. Light always travels about 300,000,000 meters per second in vacuum. If you are referring to frequency, then frequency is measured in Herz, which is inverse seconds. Perhaps you are referring to short pulses of light and the time refers to how long the emitter is turned on. In this context, picosecond pulsed lasers are called ultrafast lasers. It is the laser that is fast, that is, it can turn on and off quickly. The light itself is not fast or slow, but always travels at the same speed. A pulse of light that is created by a picosecond laser is more accurately referred to as a short pulse. Detecting short pulses is done the same way as regular light: having it interact with matter. The tricky part is if you want the high resolution that short short pulses offer, you have to have high-speed electronic circuits to process the high-speed interaction of the pulse with the detector's material.
