Thin-film laser with a two-dimensional diffraction grating

Luk'yanova, L I; Luk'yanov, V N; Shelkov, N V; Yakubovich, S D

doi:10.1070/qe1979v009n04abeh008918

Cited by 10 publications

(2 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The P(i,A) of Eq. (1) is, on the other hand, higher for heavy clusters than the ones by Luk'yanov and Titov, 7 and I have also tested much larger cluster sizes to "help" the model. The FM band in Fig.…”

Section: Edv/mentioning

confidence: 81%

Clusters and Tubes in Multiparticle Production from Nuclear Targets

Fredriksson

1980

Phys. Rev. Lett.

View full text Add to dashboard Cite

Recent data on backward pion production in 0.8-4.89-GeV proton-nucleus collisions are analyzed within the scope of models where target nucleons react collectively. It is shown that the nuclear-size dependence in data is a sensitive probe of the effective target mass. The experimental results hint at a synthesis of the cluster ("fluctuon") model and the collective tube model. PACS numbers: 13.85. Kf, 12.40.Cc, 25.40.Rb, 24.10.Dp In a recent Lawrence Berkeley Laboratory experiment Schroeder etal. 1 measured the backward yield of pions inp +A-^(180°) +X at kinetic energies 7^ = 0.8-4.89 GeV and with nuclear targets having A = 12-207. Special attention was given to the so-called cumulative production discovered by Baldin etal. in 1971. 2 This occurrence of pions with T^>T^{NN^NNn) has inspired a vast amount of theoretical work. Many theories for high-energy collisions with nuclei are built on intuitive pictures of the space-time development of a hadronic collision. 3 Most, of these are expected to work only when the nucleus is Lorentz contracted to a thickness of less than around 1 fm in the projectile rest system, or alternatively, when a typical reaction time exceeds the time which the projectile needs to pass the whole nucleus. As this happens only at T P <;A 1/3 GeV, the data of Ref. 1 cover an interesting transition region in T p .The data demonstrate three clear energy dependences from 0.8 to 4.89 GeV. First, the ratio 7r"/7r + of produced pions grows from 0.3 to 1. Second, the pion spectrum obeys E da/d 3 p ~ exp(-T ff / T 0 ) with T 0 growing from 30 to 60 MeV. Third, the A dependence changes. One finds that Edo/ d 3 p ~A n {T v ) at fixed T\. At ^ = 0.8 GeV the exponent n~ 0.8 for all T v . At T p = 4.89 GeV there is, however, an increase in n{T^) with T".. For T\ «2.5T ff max one finds n* 1.2, which is a considerable enhancement compared to the 0.8-GeV data. All these trends indicate that there is a limiting situation at infinite energies which seems to be reached already in the 8.4-GeV data of Baldin et al. 4 and perhaps even in the 4.89-GeV data.The aim of this Letter is to show that the A dependence serves as a sensitive test of theoretical models of the nuclear response in high-energy collisions with nuclei. The slope parameter T 0 and the ratio 7r"Ar + , taken on a fixed nucleus, do not play this role. They instead probe the nature of the quark reaction responsible for cumulative production.There are two different ways of explaining the existence of cumulative pions: Either the effective target is not stationary or it is more massive than a single nucleon.The conclusion from models where nucleonic Fermi motion is held responsible for cumulative production is that "too many" fast nucleons are needed. I will not analyze these models, because any data can naturally be fitted with some Fermi motion. Data show that such a distribution would have to be strongly A dependent at 4.89 GeV but virtually A independent at 0.8 GeV. This is hard to understand since the Fermi motion depends only on the nuclear d...

show abstract

Section: Edv/mentioning

confidence: 81%

Clusters and Tubes in Multiparticle Production from Nuclear Targets

Fredriksson

1980

Phys. Rev. Lett.

View full text Add to dashboard Cite

show abstract

“…A more elegant method for mode selection is the use of two-dimensionally ͑2D͒ nanopatterned substrates giving rise to a 2D distributed feedback ͑2D-DFB͒ or in other words a 2D photonic band structure. 10,11,16,17 In this letter we report on the laser performance of a surface emitting 2D photonic crystal laser utilizing an embossed nanopatterned substrate. As the active laser material we use the conjugated ladder type poly͑p-phenylene͒ ͑LPPP͒ polymer.…”

mentioning

confidence: 99%

A nearly diffraction limited surface emitting conjugated polymer laser utilizing a two-dimensional photonic band structure

Riechel

Kallinger

Lemmer

et al. 2000

Applied Physics Letters

200

117

View full text Add to dashboard Cite

We have fabricated a mechanically flexible conjugated polymer laser utilizing distributed feedback due to a two-dimensional photonic band structure. An ultraviolet-embossing process is used for nanopatterning a plastic substrate. On top we spin-coat a ladder-type poly(p-phenylene) as the active laser medium. Upon optical pumping, we observe a low threshold and nearly diffraction limited monomode laser emission perpendicular to the surface. Our results are explained within a Laue formulation for the feedback mechanism in the two-dimensional organic photonic crystal.

show abstract

Introduction and Background

Carlson

1994

Monolithic Diode-Laser Arrays

View full text Add to dashboard Cite

Thin-film laser with a two-dimensional diffraction grating

Cited by 10 publications

References 1 publication

Clusters and Tubes in Multiparticle Production from Nuclear Targets

Clusters and Tubes in Multiparticle Production from Nuclear Targets

A nearly diffraction limited surface emitting conjugated polymer laser utilizing a two-dimensional photonic band structure

Introduction and Background

Contact Info

Product

Resources

About