Question

What is first order diffraction?

Answer 1

Hint: In optics, a diffraction grating is a periodic optical component that divides and diffracts light into several beams travelling in various directions. The colouring that is developing is a type of structural coloration. The grating serves as a dispersive element since the directions of these beams are determined by the spacing of the grating and the wavelength of the light. Gratings are widely employed in monochromators and spectrometers as a result of this.

Complete step-by-step solution:
Traveling wave phenomena include interference and diffraction. When light is forced to travel through a small slit or pinhole, or when it goes through a sharp-edged obstacle, its wave nature is revealed. Under extreme magnification, the shadow of a razor blade, for example, appears to be a sequence of tightly spaced brilliant and black bands. A diffraction pattern is a collection of bands. When various waves are at the same location in space at the same time, they reinforce or cancel each other, resulting in diffraction and interference.
Because the wavelength of blue light is shorter than that of red light, the bright and dark bands in the diffraction pattern of the razor's edge are closer together in blue light. A brilliant beam straight ahead and a succession of beams to either side at angles where the light waves from neighbouring slits reinforce each other would result from the diffraction of a narrow beam of light (equivalent to a single wavelength) with the assistance of a grating. When the difference in pathlength of light from neighbouring slits of the grating is the same wavelength on both sides, the first brilliant picture appears. The first order diffraction maxima is a term used to describe this phenomenon. The study of distinct wavelengths of light is made possible by diffraction through a set of closely spaced slits (called a grating). A brilliant beam straight ahead and a succession of beams to either side at angles where the light waves from neighbouring slits reinforce each other are produced by diffraction of a narrow beam of light of a single wavelength by a grating. The "first order" diffraction maximum occurs when the difference in the pathlength of light from neighbouring slits of the grating is one wavelength.

Note: Another brilliant picture appears when the pathlength difference is two wavelengths (the second order diffraction maximum). The maxima are at greater angles when longer wavelength light is utilised. When various wavelengths of light are employed, the distinct wavelengths (colours) are separated. A diffraction grating may be thought of as a "super prism" since the colour separation is considerably greater than with a prism.