Herriott multipass cell with spherical mirrors and method for making it

摘要

A method for making a Herriott cell comprises a step of preparing two concave mirrors (3) separated by a first distance D1 and having the same spherical curvature whose radius of curvature r is determined according to the first distance D1 and a first length L1 of a predetermined optical path that a beam of light (R) completes inside the cell, the beam of light (R) covering the first length L1 inside the cell in a predetermined first number of revolutions N1 and the step of preparing an element (5) for moving one mirror (3) relative to the other, for moving the two mirrors (3) towards or away from each other by at least a quantity Q1 which defines a second distance D2 between the mirrors (3). The second distance D2 is determined according to the radius of curvature r of the mirrors (3) and a second length L2 of the optical path that the beam of light (R) completes inside the cell, the beam of light (R) covering the second length L2 in a second number of revolutions N2 which is greater than or less than the first number of revolutions.