English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Hoping to develop a future primary standard of length to use for precision interferometric length measurement, a frequency-stabilized He-Ne laser has been made. The frequency of the 0.633ƒÊm output is locked to one of the hyperfine components of an absorption line of moleculer iodine 127I2 by the method of saturated absorption. The laser cavity in which the absorption cell of iodine is placed, is servo-controlled by dual feedback loops; one is for proportional control by a piezoelectric transducer, and the other is for on-off control driving a specially designed fine tuning apparatus with a parallel spring system until the servo error is reduced to less than a set value. The stability of the frequency is evaluated by Allan variance and standard deviation measurements of the beat frequency between two stabilized lasers. Results of the measurement for five hours and a half give an Allan variance of 8kHz for a 10 second averaging

Frequency Stabilization of the He-Ne Laser by Means of Saturated Absorption in Iodine