One-fourth double-wave-plate phase retarder

Abstract

The invention discloses a one-fourth double-wave-plate phase retarder which is capable of realizing achromatic aberration. The one-fourth double-wave-plate phase retarder is characterized in that the double-wave-plate phase retarder is composed of two one-fourth zero-level wave plates made of same materials or different materials, the zero-level wave plates are parallelly arranged along optical axes, an included angle formed by the optical axes is 45 degrees, and central wavelengths of the one-fourth zero-level wave plates are within a waveband range and meet the condition that the maximum value of difference values between phase retardation quantity delta e (lambda), corresponding to each wavelength point within the waveband range, of a double-wave plate formed by the zero-level wave plates and an ideal phase retardation quantity value pi/2. Compared with existing double-wave-plate phase retarders, the one-fourth double-wave-plate phase retarder has the advantages that the optical axes of the zero-level wave plates are combined according to 45 degrees instead of 90 degrees, so that the acquired double-wave-plate phase retarder has better characteristics like achromatic aberration within full-wave band and can meet using requirements of wide-spectrum optical systems in spectrum ellipsometry and the like.

Description

technical field [0001] The invention belongs to the technical field of optical phase retarders, in particular to a quarter double-wave plate phase retarder, which is suitable for optical systems such as ellipsometry. Background technique [0002] Optical phase retarder is an optical element commonly used in the field of optical instrument design and optical measurement. It can make the two perpendicular components of polarized light produce an additional optical path difference (or phase difference), which can be used to change the polarization state of light waves (for example, from linearly polarized light to circularly polarized light, from elliptically polarized light to linearly polarized light, etc.), or to examine the polarization state of a light wave. Optical phase retarders include liquid crystal phase retarders, Fresnel total reflection prism phase retarders, wave plate phase retarders, etc. [0003] Wave plate is the simplest and most commonly used optical phase...

AI Technical Summary

Problems solved by technology

However, this composite wave plate requires at least 3 wave plates to be combined, and usually 6 or more wave plates are used in order to achieve better results, which increases the difficulty and cost of processing

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