Discharge-driven 46.9-nm amplifier with gain-length approaching saturation

Rocca, J. J.; Marconi, M. C.; Chilla, J. L. A.; Clark, Douglas P.; Tomasel, F.G.; Shlyaptsev, Vyacheslav N.

doi:10.1109/2944.473682

Cited by 18 publications

(9 citation statements)

References 16 publications

(2 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A fit of the data corresponding to plasma column lengths up to 11.5 cm with the Linford formula [18] yields a gain coefficient g 1.16 cm 21 , a gain value that is close to that of previous measurements [15]. Saturation of the intensity is observed at a gainlength product of about 14.…”

mentioning

confidence: 51%

“…Recent optimization of the capillary discharge scheme, which has the advantages of a relatively large gain volume and long gain duration, allowed amplification at 46.9 nm to reach 14 gain-length products [15], but no demonstration of substantial laser energy extraction was realized. In this Letter we report the generation of laser pulse energies up to 30 mJ at 46.9 nm in the plasma column of a fast compressional capillary discharge and the first clear evidence of gain saturation of a table-top soft x-ray amplifier.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Energy Extraction and Achievement of the Saturation Limit in a Discharge-Pumped Table-Top Soft X-Ray Amplifier

et al. 1996

View full text Add to dashboard Cite

We report the generation of laser pulse energies up to 30 mJ at 46.9 nm in the plasma column of a fast compressional capillary discharge. Double pass experiments using an iridium mirror achieved a gain-length product greater than 25. The results provide the first clear evidence of saturated operation of a table-top soft x-ray amplifier. [S0031-9007(96) PACS numbers: 42.55. Vc, 52.55.Ez, 52.75.Va A major goal in ultrashort wavelength laser research is the development of practical laser sources that can impact applications. Of particular interest is the demonstration of compact "table-top" amplifiers capable of generating soft x-ray pulses of substantial energy. Such development motivates the demonstration of gain media generated by compact devices that can be successfully scaled in length to reach gain saturation. At this condition, which occurs when the laser intensity reaches the saturation intensity, a large fraction of the energy stored in the laser upper level can be extracted. To date, gain saturation had only been achieved in a few soft x-ray laser transitions in plasmas generated by some of the world's largest laser facilities [1][2][3][4].While gain in soft x-ray lines has been reported in several compact systems [5][6][7][8][9][10][11][12][13] only in three cases the gain-length product was measured to be greater than 5 [5][6][7]. These include the observation of amplification at 46.9 nm in Ne-like Ar by our group in a plasma column generated by a fast capillary discharge [5,14], and the demonstration of gain at 41.8 nm in Pd-like Xe and at 32.6 nm in Ne-like Ti in plasmas generated by relatively compact terawatt class femtosecond and picosecond laser facilities, respectively [6,7]. In all cases, however, the laser energy extraction from table-top amplifiers has been small and detection of the laser lines was performed with high sensitivity detectors such as microchannel plate (MCP) intensifiers.A next major step in the development of compact ultrashort wavelength lasers consists in advancing from gain observations to the demonstration of substantial laser output energies. Depending on the specific amplifier characteristics, this amounts to overcoming barriers that are imposed by small gain volumes and short plasma lengths, by short duration of the gain, or by axial plasma inhomogeneities and limiting refraction effects.Recent optimization of the capillary discharge scheme, which has the advantages of a relatively large gain volume and long gain duration, allowed amplification at 46.9 nm to reach 14 gain-length products [15], but no demonstration of substantial laser energy extraction was realized. In this Letter we report the generation of laser pulse energies up to 30 mJ at 46.9 nm in the plasma column of a fast compressional capillary discharge and the first clear evidence of gain saturation of a table-top soft x-ray amplifier. Single pass amplification experiments yielded laser pulse energies up to 6 mJ. Greater energies were obtained by using an iridium mirror, in the first clearly successful d...

show abstract

mentioning

confidence: 51%

mentioning

confidence: 99%

Energy Extraction and Achievement of the Saturation Limit in a Discharge-Pumped Table-Top Soft X-Ray Amplifier

et al. 1996

View full text Add to dashboard Cite

show abstract

“…1, corresponding to the amplification of the 46.9 nm line of Ne-like Ar in a discharge-created plasma, the laser line intensity increases with a gain coefficient g Ϸ0.92 cm Ϫ1 until saturation is reached at lϷ15 cm. 70,83 In conclusion, to achieve saturated soft x-ray amplification in a single-or double-pass amplifier the gain coefficient must be, depending on the length of the plasma, 1-3 orders of magnitude larger than that typically encountered in most visible gas lasers. 88 Moreover, the fundamental physics of the generation of amplification by stimulated emission determines a dramatic upward scaling of the power density deposition required to obtain substantial gain at ultrashort wavelengths.…”

Section: A Pump Power Requirements and Scaling Lawsmentioning

confidence: 99%

“…While research towards the development of table-top x-ray lasers based on nanosecond pulse laser drivers continues to date, 80 much of the recent effort has shifted towards the use of small-scale high power ultrafast laser drivers [74][75][76][77][78]216 and compact high power discharges. 17,[68][69][70][81][82][83]124,[152][153][154][155] New opportunities for the efficient pumping of table-top soft x-ray lasers have arisen from the development of compact, very high power ultrafast optical lasers based on the technique of chirped-pulse amplification ͑CPA͒, and from the demonstration of highly ionized capillary discharge plasma columns of unprecedented axial uniformity. CPA of ultrashort laser pulses presently allows for the generation of multiterawatt peak powers from tabletop systems operating at repetition rates of typically 10 Hz.…”

Section: Present Status Of Table-top Driversmentioning

confidence: 99%

“…The advances in pump sources include the development of multiterawatt table-top optical laser systems based on chirped pulse amplification [62][63][64][65] and fast capillary discharges capable of generating highly ionized plasma columns with very high uniformity and length-to-diameter aspect ratios approaching 1000 to 1. [66][67][68][69][70] Also contributing to the progress towards practical table-top x-ray lasers is the achievement of very important reductions in the laser pump energy required for lasing, [72][73][74][75][76][77][78][79][80] to less than 1J. [72][73][74][75]80 This is in part the result of the implementation of excitation mechanisms that take full advantage of the high intensity and short pulse width of new ultrashort pulse optical laser systems.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Table-top Soft X-Ray Lasers

Rocca

2016

Conference on Lasers and Electro-Optics

View full text Add to dashboard Cite

This article reviews the progress in the development of practical table-top sources of soft x-ray laser radiation. The field is rapidly approaching the stage at which soft x-ray lasers sufficiently compact to fit onto a normal optical table will be routinely utilized in science and technology. This is the result of recent advances in the amplification of soft x-ray radiation in both compact laser-pumped and discharge-pumped devices. The use of excitation mechanisms that take full advantage of new ultrafast high power optical laser drivers and multiple pulse excitation schemes has resulted in the demonstration of saturated soft x-ray amplification at wavelengths as short as 14 nm using several Joule of laser-pump energy. Moreover, several schemes have demonstrated significant gain with only a fraction of a Joule of laser-pump energy. In addition, the demonstration of saturated table-top soft x-ray lasers pumped by very compact capillary discharges has shattered the notion that discharge-created plasmas are insufficiently uniform to allow for soft x-ray amplification, opening a route for the development of efficient, high average power soft x-ray lasers. Recently, a table-top capillary discharge laser operating at 46.9 nm has produced millijoule-level laser pulses at a repetition rate of several Hz, with a corresponding spatially coherent average power per unit bandwidth comparable to that of a beam line at a third generation synchrotron facility. This review summarizes fundamental and technical aspects of table-top soft x-ray lasers based on the generation of population inversions in plasmas, and discusses the present status of development of specific laser systems.

show abstract