Ultrafast Laser Material Processing For Photonic Applications

Femtosecond Laser Direct Writing (FLDW) is a viable technique for producing photonic devices in bulk materials. This novel manufacturing technique is versatile due to its full 3D fabrication capability. Typically, the only requirement for this process is that the base material must be transparent to the laser wavelength. The modification process itself is based on non-linear energy absorption of laser light within the focal volume of the incident beam. This thesis addresses the feasibility of this technique for introducing photonic structures into novel dielectric materials. Additionally, this work provides a deeper understanding of the lightmatter interaction mechanism occurring at high pulse repetition rates. A novel structure on the sample surface in the form of nano-fibers was observed when the bulk material was irradiated with high repetition rate pulse trains. To utilize the advantages of the FLDW technique even further, a transfer of the technology from dielectric to semiconductor materials is investigated. However, this demands detailed insight of the absorption and modification processes themselves. Experiments and the results suggested that non-linear absorption, specifically avalanche ionization, is the limiting factor inhibiting the application of FLDW to bulk semiconductors with today’s laser sources

Технологические решения для строительства наклонно-направленной скважины глубиной 2900 метров на Медвежьем газовом месторождении (ЯНАО)

Исследуем объект Медвежье газовое месторождение. Цель данной работы – спроектировать газовую скважину на Медвежьем месторождении. В процессе работы был составлен проект на строительство эксплуатационной газовой скважины глубиной 2900 м на Медвежьем месторождении. Разработаны мероприятия по организации строительства, охране труда и окружающей среды. В работе рассмотрен вопрос анализа конструкций зарубежных и российских калибраторов.Explore the object Bear's gas field. The aim of this work is to design a gas well at the Bear field. In the course of the work, a project was drawn up for the construction of an operational gas well with a depth of 2,900 m at the Bear field. Measures have been developed for the organization of construction, labor protection and the environment. The paper considers the analysis of the designs of foreign and Russian calibrators

Material Response Of Semiconductors Irradiated With Ir Ultrashort Laser Pulses

We utilize near- and mid-IR ultrafast laser radiation to investigate the processing of crystalline silicon with different dopants. A numerical model is adopted to simulate the material response depending on the wavelength and the dopant concentration

Multiple Beam Splitter Using Volumetric Multiplexed Fresnel Zone Plates Fabricated By Ultrafast Laser-Writing

A simple approach to producing a 1 × N beam splitter is demonstrated by fabricating a volumetric multiplex phase Fresnel zone plate in bulk transparent material. This comprised four layers of zone plates created in borosilicate glass by femtosecond laser direct-writing, each shifted laterally relative to the illumination axis, creating four separate beamlets. Since the power transmitted in each beamlet is proportional to the diffraction efficiency of the corresponding zone plate, the power ratios can be customized by adjusting the fabrication parameters of each layer. This approach demonstrates the potential of femtosecond laser direct-writing for the fabrication of complex optical elements in transparent media as components of integrated monolithic photonic devices. © 2012 Optical Society of America

Directly Laser-Written Integrated Photonics Devices Including Diffractive Optical Elements

Femtosecond laser-written integrated devices involving Fresnel Zone Plates (FZPs) and waveguide arrays are demonstrated as built-in optical couplers. These structures were fabricated in borosilicate glass using a direct laser writing technique. The optical properties of these integrated photonic structures were investigated using CW lasers and high-resolution CCDs. For a single FZP coupled to a single waveguide, the overall coupling efficiency was 9%. A multiplexed optical coupler composed of three FZP layers was demonstrated to couple three waveguides simultaneously in a waveguide array. Structures of this type can be used as platforms for multichannel waveguide coupling elements or as microfluidic sensors that require higher light collecting efficiency

Femtosecond Single-Pulse Absorption in Semiconductors with varying Dopant Concentration

The influence of dopant concentration on the absorption of femtosecond mid-IR pulses is described. The measured results are compared to a theoretical absorption model

Increase Of Ablation Rate Using Burst Mode Femtosecond Pulses

We investigate the ablation rates of metals and dielectrics using a Ti:Sapphire oscillator. Prior work on burst ablation has been performed using high-power lasers and significant increases were observed. These two modalities will be compared. ©2007 Optical Society of America

Increase Of Ablation Rate Using Burst Mode Femtosecond Pulses

We investigate the ablation rates of metals and dielectrics using a Ti:Sapphire oscillator. Prior work on burst ablation has been performed using high-power lasers and significant increases were observed. These two modalities will be compared. © 2007 Optical Society of America

Increase of ablation rate using burst mode femtosecond pulses

We investigate the ablation rates of metals and dielectrics using a Ti:Sapphire oscillator. Prior work on burst ablation has been performed using high-power lasers and significant increases were observed. These two modalities will be compared. © 2007 Optical Society of America

Increase Of Ablation Rate Using Burst Mode Femtosecond Pulses

We investigate the ablation rates of metals and dielectrics using a Ti:Sapphire oscillator. Prior work on burst ablation has been performed using high-power lasers and significant increases were observed. These two modalities will be compared. © 2007 Optical Society of America