A laser has a wavelength of 645 nm. A grating and a lens are used to split the beam into three parallel beams spaced 1.85 cm apart. What is the minimal value of the slit spacing so that the grating produces three and only three beams? um

4. a. Determine the size of the Airy disk (in m) found at the center of a 4.00-cm diameter lens, with a focal length of 15.0 cm. Assume the incident light wavelength is the middle of the visible spectrum = 550. nm. b. In observational astronomy, we assume that stars, being so far away, are point sources of light, and that the image of a star in a telescope eyepiece is therefore also a point. Given that the average human near-field resolution is 0.10 mm, does your result in part a justify this assumption? Explain your answer, using the value from part a. c. Assume that the objective lens diffraction limit is the only one that matters on a telescope (actually a good assumption, not justified here). What is the angular size (in radians) of the smallest object that can be truly observed as a disk on the 4.00-cm telescope in part a? Can Jupiter (maximum angular size = 51 arc-seconds) be seen as a disk through this telescope? Note that real telescopes have glass or mirror imperfections which…

Irina finds an unlabeled box of fine needles, and wants to determine how thick they are. A standard ruler will not do the job, as each needle is less than a millimeter thick. So, to find the thickness, she uses a needle to poke a hole in a piece of brown construction paper. Then, she positions a 640 nm laser pointer to shine through the hole and project a circular diffraction pattern on a wall 20.2 m away. She then uses her ruler to measure that the central bright circle is 15.7 cm in diameter. What diameter does Irina calculate for the needle?

Laser light is shone onto two slits separated by a distance of 8.0mm. The light is shone onto a screen 5.7m away. The distance to the m=3 bright fringe measured from the central bright spot is 7.9cm. Find the wavelength of the laser in nm.