A He–Ne laser beam is reflected from the surface of a CD onto a wall. The brightest spot is the reflected beam at an angle equal to the angle of incidence. However, fringes are also observed, at different angles of reflection. The wavelength of a He-Ne laser is λ = 633 nm.    If the wall is 1.35 m from the CD, and the first fringe is 0.58 m from the central maximum, what is the spacing of grooves on the CD, in meters?  d =

One way to determine the index of refraction of a gas is to use an interferometer. As shown below, one of the beams of an interferometer passes through a glass container that has a length of L = 1.8 cm. Initially the glass container is a vacuum. When gas is slowly allowed into the container, a total of 7571 dark fringes move past the reference line. The laser has a wavelength of 687 nm (this is the wavelength when the light from the laser is moving through a vacuum). Laser Mirror Glass Container Beam Splitter Diffraction Pattern Mirror A.) Determine how many wavelengths will fit into the glass container when it is a vacuum. Since the light passes through the container twice, you need to determine how many wavelengths will fit into a glass container that has a length of 2L. number of wavelengths (vacuum) = B.) The number of dark fringes is the difference between the number of wavelengths that fit in the container (length of 2L) when it has gas and the number of wavelengths that fit in…

A helium-neon laser (2=632.8 nm) is used to calibrate a diffraction grating. If the first-order maximum occurs at 20.0°, what is the spacing between adjacent grooves in the grating? (In this problem, assume that the light is incident normally on the grating.) um

A laser beam is normally incident on a diffraction grating. The wavelength of the incident light is 1 = 560 nm, and the third-order maximum of the diffraction pattern is measured to be at an angle of 32.0°. (a) What is the density of rulings for the grating (in grooves/cm)? grooves/cm (b) Determine the total number of primary maxima that can be observed in this situation. primary maxima Need Help? Read It