High-temperature recording of strong permanent diffraction gratings in copper-doped lithium niobate crystals based on a zero-electric-field photorefractive effect

U. Hartwig; K. Peithmann; B. Sturman; K. Buse

doi:10.1117/12.624645

7 October 2005 High-temperature recording of strong permanent diffraction gratings in copper-doped lithium niobate crystals based on a zero-electric-field photorefractive effect

U. Hartwig, K. Peithmann, B. Sturman, K. Buse

Author Affiliations +

Proceedings Volume 5911, Photorefractive Fiber and Crystal Devices: Materials, Optical Properties, and Applications XI; 59111F (2005) https://doi.org/10.1117/12.624645
Event: Optics and Photonics 2005, 2005, San Diego, California, United States

Abstract

Diffraction gratings, which do not rely on the electro-optic effect, are recorded in copper-doped lithium niobate crystals: At elevated temperatures (approx. 180 °C), the crystals are illuminated by an interference pattern. The light pattern excites electrons from filled Cu⁺ traps into the conduction band. They are captured by empty Cu²⁺ traps elsewhere. The resulting electric fields are compensated by ions, such as H⁺, that are thermally mobilized. Therefore the redistribution of electrons can continue which finally results in a high modulation of Cu⁺ and Cu2+ traps. This process is called "thermal fixing" and is known since decades. However, here we report about a novel and relevant effect resulting from the electron concentration grating. The Cu⁺ traps absorb mainly in the near UV and visible spectral range, Cu²⁺ traps have their absorption peak in the near infrared. A modulation of Cu⁺ and Cu²⁺ trap concentrations therefore results in a pronounced absorption modulation. This immediately implies an absorption grating, but another consequence is even more dramatic: The Kramers-Kronig relations link changes of the absorption to changes of the refractive index. Thus the narrow absorption bands of copper in lithium niobate lead to refractive index changes over a vast wavelength range. Maximum index changes of the order of 10⁻⁴ are achieved. The resulting gratings can be recorded in any crystal orientation and are of interest for applications in non-linear optics.

Citation Download Citation

U. Hartwig, K. Peithmann, B. Sturman, and K. Buse "High-temperature recording of strong permanent diffraction gratings in copper-doped lithium niobate crystals based on a zero-electric-field photorefractive effect", Proc. SPIE 5911, Photorefractive Fiber and Crystal Devices: Materials, Optical Properties, and Applications XI, 59111F (7 October 2005); https://doi.org/10.1117/12.624645

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
8 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Copper

Absorption

Diffraction gratings

Crystals

Diffraction

Modulation

Lithium niobate

Show All Keywords

Keywords/Phrases

Search In:

Publication Years