Optical damage thresholds of single-mode fiber-tip spintronic terahertz emitters

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989100%3A27360%2F24%3A10255036" target="_blank" >RIV/61989100:27360/24:10255036 - isvavai.cz</a>

Result on the web

<a href="https://opg.optica.org/oe/fulltext.cfm?uri=oe-32-14-24826&id=552793" target="_blank" >https://opg.optica.org/oe/fulltext.cfm?uri=oe-32-14-24826&id=552793</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1364/OE.525747" target="_blank" >10.1364/OE.525747</a>

Result language

angličtina

Original language name

Optical damage thresholds of single-mode fiber-tip spintronic terahertz emitters

Original language description

Spintronic terahertz emitters (STEs) are gapless, ultrabroadband terahertz sources that can be driven within a wide pump-wavelength and repetition-rate range. While STEs driven by strong pump lasers operating at kilohertz repetition rates excel in generating high electric field strengths for terahertz spectroscopy or ellipsometry, newly advancing technologies such as ultrafast modulation of terahertz polarization, scanning tunneling microscopy, laser terahertz emission nanoscopy, and fully fiber-coupled integrated systems demand an STE pumping at megahertz repetition rates. In all these applications the available terahertz power is ultimately limited by the STE&apos;s optical damage threshold. However, to date, only very few publications have targeted this crucial topic and investigations beyond the kilohertz repetition-rate regime are missing. Here, we present a complete study of our single-mode fiber-tip STEs&apos; optical damage thresholds covering the kilohertz, megahertz, and gigahertz repetition-rate regimes as well as continuous-wave irradiation. As a very important finding, we introduce the necessity of classifying the optical damage threshold into two regimes: a low-repetition-rate regime characterized by a nearly constant fluence threshold, and a high-repetition-rate regime characterized by an antiproportional fluence dependence (&quot;average-power threshold&quot;). For our single-mode fiber-tip STEs, the transition between these regimes occurs around 4 MHz. Moreover, we present a cohesive theory of the damaging thermodynamical processes at play and identify temperature-driven inter-layer diffusion as the primary cause of the STE failure. These findings are substantiated by atomic force microscopy, infrared scattering-type scanning near-field optical microscopy, and scanning transmission electron microscopy measurements. This new level of understanding offers a clear optimization lever and provides valuable support for future advancements in the promising field of spintronic terahertz emission.

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10300 - Physical sciences

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2024

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Optics Express

ISSN

1094-4087

e-ISSN

—

Volume of the periodical

32

Issue of the periodical within the volume

16

Country of publishing house

US - UNITED STATES

Number of pages

13

Pages from-to

24826-24838

UT code for WoS article

001278801500010

EID of the result in the Scopus database

2-s2.0-85198358950