Lecture

Atomic Clocks: Optical Frequency Standards

Graph Chat

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

Description

This lecture covers the principles of atomic clocks, focusing on optical frequency standards. Topics include the history of timekeeping, the transition from mechanical to atomic era, and the use of optical frequencies for superior frequency standards. The instructor discusses the operation of cesium clocks, the measurement of carrier envelope frequency, and the potential of optical clocks to surpass microwave standards. The lecture also explores the concept of timekeeping using higher frequencies and the challenges in measuring optical frequencies accurately.

Official source

Related concepts (32)

Atomic clock

An atomic clock is a clock that measures time by monitoring the resonant frequency of atoms. It is based on atoms having different energy levels. Electron states in an atom are associated with different energy levels, and in transitions between such states they interact with a very specific frequency of electromagnetic radiation. This phenomenon serves as the basis for the International System of Units' (SI) definition of a second:The second, symbol s, is the SI unit of time.

Laser

A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word laser is an anacronym that originated as an acronym for light amplification by stimulated emission of radiation. The first laser was built in 1960 by Theodore Maiman at Hughes Research Laboratories, based on theoretical work by Charles H. Townes and Arthur Leonard Schawlow. A laser differs from other sources of light in that it emits light that is coherent.

Clock

A clock or chronometer is a device used to measure and indicate time. The clock is one of the oldest human inventions, meeting the need to measure intervals of time shorter than the natural units such as the day, the lunar month, and the year. Devices operating on several physical processes have been used over the millennia. Some predecessors to the modern clock may be considered "clocks" that are based on movement in nature: A sundial shows the time by displaying the position of a shadow on a flat surface.

Radio clock

A radio clock or radio-controlled clock (RCC), and often (incorrectly and colloquially) referred to as an "atomic clock", is a type of quartz clock or watch that is automatically synchronized to a time code transmitted by a radio transmitter connected to a time standard such as an atomic clock. Such a clock may be synchronized to the time sent by a single transmitter, such as many national or regional time transmitters, or may use the multiple transmitters used by satellite navigation systems such as Global Positioning System.

Laser safety

Laser radiation safety is the safe design, use and implementation of lasers to minimize the risk of laser accidents, especially those involving eye injuries. Since even relatively small amounts of laser light can lead to permanent eye injuries, the sale and usage of lasers is typically subject to government regulations. Moderate and high-power lasers are potentially hazardous because they can burn the retina, or even the skin.

Related lectures (40)

History of lasers: Lorentz model for atom/light interaction

Explores the history of lasers and the Lorentz model for atom-light interaction.

Ultrafast Laser Beam Steering

Explores ultrafast lasers, beam steering technologies, chirped pulses, and mode-locking for high laser powers.

Laser Fundamentals: Applications and Technologies

Provides an overview of laser fundamentals, applications, and technologies relevant to engineering and manufacturing processes.

Gain saturation

Explores gain saturation in laser systems and the dynamics of atoms in different energy levels, emphasizing the balance between pumping and emission processes.

Laser Fundamentals: Principles and Applications for Engineers