91影视

When monochromatic light sent through a narrow slit, produces a diffraction pattern on a distant screen which is single slit diffraction.

Condition of dark fringes (destructive interference) in single slit diffraction is as follow,

$\mathbf{补蝉颈苍胃}\mathbf{=}\mathbf{苍位}$

Where is slit width,$\mathbf{胃}$ is the diffraction angle of minima; is the order of minima andis wavelength of the light.

If the diffraction angle for 1^st minima is $90掳$then there will be no minima in field of view as for 1^st minima diffracted light become parallel to slit and screen.

No minima occur when$胃=90掳$ . From this one can say,

$$\begin{gathered} \mathrm{asin}90掳=1脳\mathrm{位} \\ \mathrm{a}=\mathrm{位} \end{gathered}$$

The above equation is the criterion for 鈥渘o-minima鈥�.

Therefore, Maximum slit width for which there will be no minima is equal to the wavelength of light.