Use of optical polarization states to control a ponderomotive phase plate

US11990313B2 · kind B2 · utility

Assignee

• The Regents of the University of California · US

Inventors

• Jeremy J. Axelrod · Berkeley, US
• Carter Turnbaugh · Berkeley, US
• Sara Campbell · Exeter, US
• Osip SCHWARTZ · Newark, US
• Robert M. Glaeser · Berkeley, US
• Holger Mueller · Jena, DE

Key dates

• Filing date: Sep 10, 2020
• Grant date: May 21, 2024
• Expiry date: Feb 11, 2041

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01J2237/2614
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

A ponderomotive phase plate, also called a laser phase plate or standing wave optical phase plate, has a first minor and a second minor that define an optical cavity. An electron beam passes through a focal spot of the optical cavity. A laser with variable polarization angle of laser light is coupled to the optical cavity. A standing wave of polarized laser light, with an anti-node at the focal spot of the optical cavity, causes variable modulation of the electron beam. The variable modulation of the electron beam is controllable by the variable polarization angle of the laser light. In a transmission electron microscope, an image plane receives the electron beam modulated by the standing wave optical phase plate. An image formed at the image plane is based on the variable polarization angle of the polarized laser light.