Partially pumped random lasers

Jonathan Andreasen, Nicolas Bachelard, Shivakiran B.N. Bhaktha, Hui Cao, Patrick Sebbah, Christian Vanneste

Research output: Contribution to journalArticlepeer-review

26 Scopus citations

Abstract

Conventional lasers consist of two components: a gain material that is pumped in order to provide amplification of light and a cavity to provide feedback. Random lasers replace the traditional laser cavity with a random, multiple-scattering medium. This can give rise to complex lasing behavior, such as unpredictable multidirectional and multifrequency output. Controlling these systems has proved difficult and, until now, has consisted of material and structural manipulations. In random lasers, the most common pumping mechanism is an optical field, which can be applied uniformly or partially across the scattering medium. Partial pumping, referring to the restricted spatial extent of the pump applied to the gain material, is therefore quite ubiquitous in such systems. In contrast to conventional lasers, however, the impact of partial pumping can be significant in random lasers as a subset of the scattering medium is probed. In this review, we discuss state-of-the-art investigations of partially pumped random lasers. Numerical and experimental investigations of how even a simple spot profile of the pump can dramatically alter random laser output are presented. First, the simple case of partial pumping in strongly scattering systems where laser modes are spatially confined is described. Then the most common but more difficult case of weakly scattering random lasers is considered. Here, modes are spatially extended, forcing greater mode interaction and making the random laser output more difficult to predict. Finally, we review recent works that show how the pumping degree of freedom allows a general increase in control over random lasers.

Original languageEnglish
Article number1430001
JournalInternational Journal of Modern Physics B
Volume28
Issue number5
DOIs
StatePublished - 20 Feb 2014
Externally publishedYes

Bibliographical note

Funding Information:
JA acknowledges support from the Embassy of France in the United States. SNBB acknowledges support from the Agence Nationale de la Recherche (ANR) under Grant No. ANR-08-BLAN-0302-01 and the DST-Fast Track Scheme for Young Scientists. PS acknowledges support from the ANR under Grant No. ANR-08-BLAN-0302-01 and the Laboratory of Excellence within the French Program “Investments for the Future” (LABEX WIFI) under Reference ANR-10-IDEX-0001-02 PSL*. SNBB and PS acknowledge support from the Groupement de Recherche 3219 MesoImage. HC acknowledges support from the NSF under Grant Nos. ECCS1128542 and DMR120530.

Keywords

  • Random lasers
  • laser pumping
  • multiple scattering

Fingerprint

Dive into the research topics of 'Partially pumped random lasers'. Together they form a unique fingerprint.

Cite this