Session Overview |
Thursday, May 30 |
10:40 |
Single-step writing of Bragg grating waveguides in low-iron glass through fs selective pulses control
* Foroogh Jafari, Polytechnique Montreal, Canada Jean-Sébastien Boisvert, Polytechnique Montreal, Canada Raman Kashyap, Polytechnique Montreal, Canada Sébastien Loranger, Polytechnique Montreal, Canada A second-order Bragg grating (BG) is written in a low-iron glass sample with the 250 fs laser at 515 nm. Single-step writing of waveguide and BG is obtained by externally modulating the laser pulse picker using a waveform generator, thus sending a controlled number of pulses for each Bragg period. Different waveforms have been generated including frequency shift keying (FSK) and square wave with different duty cycles in order to generate waveguide segmentation by controlling the number of pulses delivered in half of the period. By carefully selecting the writing parameters, low-loss BG can be fabricated at relatively high writing speed. Also, the creation of complex and arbitrary waveforms can open a novel method to fabricate complex BG using ultrafast lasers. |
10:55 |
Ultrafast laser beam shaping - filaments and light sheets for engineering periodic diffractive structure in bulk and fibre glasses
* Peter Herman, University of Toronto, Canada Gligor Djogo, University of Toronto Pok Man Chow, University of Toronto Stephen Ho, University of Toronto Jianzhao Li, University of Toronto Yueqi Wang, University of Toronto Polina Zavyalova, University of Toronto Ultrafast laser pulses have been molded with a spatial light modulator in three dimensions to control the shape and contrast of refractive index elements and facilitate their assembly into micro-optic diffractive elements in bulk glasses and optical fibre. Both one-dimensional and two-dimensional grating arrays are presented. Laser interactions were varied from gentle modification of refractive index contrast (i.e.,'n ~ 0.01) to nano-explosions forming open nano-capillaries and nano-planes, enabling the engineering of highly functional and compact microsystems. |
11:20 |
Microresonator-Based Mode-Locked Laser with Tunable Pulse Repetition Rates
* Pavel Dmitriev, Institut National de la Recherche Scientifique - Énergie Matériaux Télécommunications, Canada Luigi Di Lauro, Institut National de la Recherche Scientifique - Énergie Matériaux Télécommunications, Canada Abdul Rahim Aadhi, Institut National de la Recherche Scientifique - Énergie Matériaux Télécommunications, Canada Imtiaz Alamgir, Institut National de la Recherche Scientifique - Énergie Matériaux Télécommunications, Canada Bennet Fischer, Institut National de la Recherche Scientifique - Énergie Matériaux Télécommunications, Canada Nicolas Perron, Institut National de la Recherche Scientifique - Énergie Matériaux Télécommunications, Canada Celine Mazoukh, Institut National de la Recherche Scientifique - Énergie Matériaux Télécommunications, Canada Piotr Roztocki, Institut National de la Recherche Scientifique - Énergie Matériaux Télécommunications, Canada Cristina Rimoldi, Institut National de la Recherche Scientifique - Énergie Matériaux Télécommunications, Canada Mario Chemnitz, Institut National de la Recherche Scientifique - Énergie Matériaux Télécommunications, Canada Armaghan Eshaghi, Huawei Technologies Canada, Canada Evgeny Viktorov, ITMO University, Russia Anton Kovalev, ITMO University, Russia Brent Little, QXP Technology Inc, China (People's Republic of) Sai Tak Chu, City University of Hong Kong, China (People's Republic of) David Moss, Optical Sciences Centre, Swinburne University of Technology, Australia Roberto Morandotti, Institut National de la Recherche Scientifique - Énergie Matériaux Télécommunications, Canada Mode-locking techniques are crucial for advancing laser applications, producing pulses with diverse duration and repetition rates. However, the generation of pulse trains with tunable repetition rates within a single laser cavity configuration remains unexplored. In our work, we demonstrate an actively mode-locked fiber-cavity laser incorporating a microring resonator to achieve pulse trains spanning nanosecond to picosecond timescales. Moreover, we show ultra-stable broadband microcombs with controllable center wavelengths for spectroscopy, metrology, and telecommunications applications. |
11:35 |
Compressed ultrafast femtography by coded-aperture sweeping
* Miguel Marquez, Institut National de la Recherche Scientifique, Canada Jingdan Liu, Institut National de la Recherche Scientifique, Canada Yingming Lai, Institut National de la Recherche Scientifique, Canada Heide Ibrahim, Institut National de la Recherche Scientifique, Canada Katherine Légaré, Institut National de la Recherche Scientifique Philippe Lassonde, Institut National de la Recherche Scientifique Xianglei Liu, Institut National de la Recherche Scientifique Michel Hehn, Institut Jean Lamour, Université de Lorraine, France Stéphane Mangin, Institut Jean Lamour, Université de Lorraine, France Grégory Malinowski, Institut Jean Lamour, Université de Lorraine, France Zhengyan Li, Huazhong University of Science and Technology, China (People's Republic of) François Légaré, Institut National de la Recherche Scientifique, Canada Jinyang Liang, Institut National de la Recherche Scientifique, Canada Single-shot real-time femtophotography has surged as a crucial tool for imaging ultrafast dynamics during their times of occurrence. However, most existing methods limit imaging speed or degraded data quality by the deployed optoelectronic devices. To overcome these limitations, we propose swept-coded aperture real-time femtophotography (SCARF) that enables, in an all-optical fashion, records of ultrafast events with a full-sequence encoding of up to 156.3 THz and a sequence depth of up to 132. We use SCARF to image ultrashort pulses through transparencies and ultrafast absorption in a semiconductor. |
11:50 |
Nonlinear Propagation of Cylindrical Vector Beams in Photonic Crystal Fibers
* Kurosh Firouzi, Simon Fraser University, Canada Alessio D'Errico, University of Ottawa, Canada Eric Brace, Simon Fraser University, Canada Pierre Lane, Simon Fraser University, Canada Gary Leach, Simon Fraser University, Canada Ebrahim Karimi, University of Ottawa, Canada Shawn Sederberg, Simon Fraser University, Canada Photonic Crystal Fibers (PCFs) have witnessed remarkable progress, and recent advancements in nonlinear optics allow us to manipulate the optical response of materials beyond linear regimes. Merging structured fibers with structured light enables precise control over the spatial, spectral, and temporal characteristics of light. This paper investigates the nonlinear propagation of femtosecond vector beam pulses through a PCF. It delves into the unique characteristics of donut-shaped beams when passed through PCFs, aiming to unravel the underlying nonlinear effects that have not been explored before. We systematically investigate the influence of incident power on the transmission efficiency, spectrum, and modal characteristics of the output vector beam. |