Q. Consider the following statements:
1.The refractive index changes periodically.
2.It occurs in nature in the form of structural coloration.
Which of the statements given above is/are correct regarding photonic crystals?
Statement 1: Photonic crystals are optical nanostructures in which the refractive index changes periodically.
Statement 2: Photonic crystals occur in nature in the form of structural coloration and animal reflectors.