Laser breakdown with millijoule trains of picosecond pulses transmitted through a hollow-core photonic-crystal fibre

Abstract

Sequences of picosecond pulses with a total energy in the pulse train of about 1 mJ are transmitted through a hollow-core photonic-crystal fibre with a core diameter of approximately 14 μm. The fluence of laser radiation coupled into the core of the fibre under these conditions exceeds the breakdown threshold of fused silica by nearly an order of magnitude. The laser beam coming out of the fibre is then focused to produce a breakdown on a solid surface. Parameters of laser radiation were chosen in such a way as to avoid effects related to the excitation of higher order waveguide modes and ionization of the gas filling the fibre in order to provide the possibility to focus the output beam into a spot with a minimum diameter, thus ensuring the maximum spatial resolution and the maximum power density in the focal spot.

Nonlinear optics of microstructure fibers

“…±ÑAEÑÃÐÞÇ ÄÑÎÑÍРÏÑÅÖÕ ÃÞÕß ËÔÒÑÎß-ÊÑÄÂÐÞ AEÎâ ÎÂÊÇÓÐÑÅÑ ÖÒÓÂÄÎÇÐËâ ÏËÍÓÑÚÂÔÕËÙÂÏË Ë ÂÕÑÏÂÏË [44],  ÕÂÍÉÇ AEÎâ ÒÇÓÇAEÂÚË ÏÑÜÐÑÅÑ ÎÂÊÇÓÐÑÅÑ ËÊÎÖÚÇÐËâ ÕÇØÐÑÎÑÅËÚÇÔÍËØ ÎÂÊÇÓÐÞØ ÔËÔÕÇÏ Ä ÙÇÎâØ ÏËÍÓÑÑÃÓÂÃÑÕÍË ÏÂÕÇÓËÂÎÑÄ [45] Ë ÎÂÊÇÓÐÑÌ ÃËÑÏÇAEË-ÙËÐÞ [46]. ®³-ÄÑÎÑÍÐÂ Ô ÔËÔÕÇÏÑÌ ÔÄâÊÂÐÐÞØ ÄÑÎÐÑÄÑAEÐÞØ ÍÂÐÂÎÑÄ Ä ÄËAEÇ ÓÇÅÖÎâÓÐÑÌ ÔÕÓÖÍÕÖÓÞ, ÑÍÓÖÉÂáÜÇÌ ÙÇÐÕÓÂÎßÐÖá ÉËÎÖ (ÕÓÇÕßâ ÔÕÓÑÍ ÕÂÃÎ.…”

Fundamental Studies of Ignition Processes in Large Natural Gas Engines Using Laser Spark Ignition

“…To the best of our knowledge, the work reported here is the first demonstration of spark formation using light delivered though fiber optics. While other related work has employed picosecond pulse trains through hollow-core photonic-crystal fibers for delivery of intense laser pulses [2], spark formation was not reported in the gas phase. Similarly, there have been no published reports of spark formation in this regime using solid step-index silica fibers.…”

Laser-Induced Breakdown Spectroscopy: Fundamentals, Applications, and Challenges

“…In these situations or when the environment is too aggressive or the access restriction makes it difficult to induce the plasma or acquire the light, fiber optic cables (FOCs) or bundles are used [44][45][46]. Although the most common optical fibers in LIBS are made of fused silica (with diameters between 50 µm and 1 mm), different kinds of fibers such as photonic-crystal fibers are used too [47]. Approaches using these coiled fibers (including plastic optical fiber (POF) ones) placed around the plasma plume are also used [48,49].…”