Waveguide lasers in Er:Yb-doped phosphate glass fabricated by femtosecond laser writing

Advanced waveguide lasers, operating both in continuous wave and pulsed regimes, have been realized in an active phosphate glass by direct writing with femtosecond laser pulses. Stable single mode operation was obtained; the laser provided more than 50 m W in single longitudinal and transverse mode operation with 21% slope efficiency. Furthermore, by combining a high gain waveguide and an innovated fiber-pigtailed saturable absorber based on carbon nanotubes, a mode-locked ring laser providing transform limited 1.6 ps pulses was demonstrated. © 2007 IEEE.

Mode-locked and single-longitudinal-mode waveguide lasers fabricated by femtosecond laser pulses in Er:Yb-doped phosphate glass

Mode-locked and single-longitudinal-mode waveguide lasers, manufactured by femtosecond laser writing in Er-Yb-doped phosphate glasses, are presented. Transform-limited 1.6-ps pulses and a cw output power exceeding 50 mW have been obtained in the two regimes. © 2007 Optical Society of America.

Q-switched modelocking using carbon nanotubes in an ultrafast laser inscribed ytterbium doped bismuthate glass waveguide laser

Passive modelocking using carbon nanotubes is achieved in a linear cavity waveguide laser realized by ultrafast laser inscription in ytterbium doped bismuthate glass. The pulses observed under a Q-switched envelope have a repetition rate of 1.5 GHz. © 2012 OSA.

Mode-locked and single-longitudinal-mode waveguide lasers fabricated by femtosecond laser pulses in Er: Yb-doped phosphate glass

Mode-locked and single-longitudinal-mode waveguide lasers, manufactured by femtosecond laser writing in Er-Yb-doped phosphate glasses, are presented. Transform-limited 1.6-ps pulses and a cw output power exceeding 50 mW have been obtained in the two regimes. © 2007 Optical Society of America.

Er3+-doped glass-polymer composite thin films fabricated using combinatorial pulsed laser deposition

Siloxane Polymer exhibits low loss in the 800-1500 nm range which varies between 0.01 and 0.66 dB cm1. It is for such low loss the material is one of the most promising candidates in the application of engineering passive and active optical devices [1, 2]. However, current polymer fabrication techniques do not provide a methodology which allows high structurally solubility of Er3+ ions in siloxane matrix. To address this problem, Yang et al.[3] demonstrated a channel waveguide amplifier with Nd 3+-complex doped polymer, whilst Wong and co-workers[4] employed Yb3+ and Er3+ co-doped polymer hosts for increasing the gain. In some recent research we demonstrated pulsed laser deposition of Er-doped tellurite glass thin films on siloxane polymer coated silica substrates[5]. Here an alternative methodology for multilayer polymer-glass composite thin films using Er3+ - Yb3+ co-doped phosphate modified tellurite (PT) glass and siloxane polymer is proposed by adopting combinatorial pulsed laser deposition (PLD). © 2011 IEEE.

UV durable colour pigment doped SmA liquid crystal composites for outdoor trans-reflective bi-stable displays

High brightness trans-reflective bi-stable displays based on smectic A (SmA) liquid crystals (LCs) can have nearly perfect transparency in the clear state and very high reflection in the scattered state. Because the LC material in use is stable under UV radiation, this kind of displays can stand for strong day-light and therefore be ideal for outdoor applications from e-books to public signage and advertisement. However, the colour application has been limited because the traditional colourants in use are conventional dyes which are lack of UV stability and that their colours are easily photo bleached. Here we present a colour SmA display demonstrator using pigments as colourant. Mixing pigments with SmA LCs and maintain the desirable optical switching performance is not straightforward. We show here how it can be done, including how to obtain fine sized pigment nano-particles, the effects of particle size and size distribution on the display performance. Our optimized pigments/SmA compositions can be driven by a low frequency waveform (∼101Hz) to a scattered state to exhibit colour while by a high frequency waveform (∼103Hz) to a cleared state showing no colour. Finally, we will present its excellent UV life-time (at least >7.2 years) in comparison with that of dye composition (∼2.4 years). The complex interaction of pigment nano-particles with LC molecules and the resulting effects on the LC electro-optical performances are still to be fully understood. We hope this work will not only demonstrate a new and practical approach for outdoor reflective colour displays but also provide a new material system for fundamental liquid crystal colloid research work. © 2012 SPIE.

1.5 GHz picosecond pulse generation from a monolithic waveguide laser with a graphene-film saturable output coupler

We fabricate a saturable absorber mirror by coating a graphenefilm on an output coupler mirror. This is then used to obtain Q-switched mode-locking from a diode-pumped linear cavity channel waveguide laser inscribed in Ytterbium-doped Bismuthate Glass. The laser produces 1.06 ps pulses at ∼1039 nm, with a 1.5 GHz repetition rate, 48% slope efficiency and 202 mW average output power. This performance is due to the combination of the graphene saturable absorber and the high quality optical waveguides in the laser glass. © 2013 Optical Society of America.

Mode-locking using right-angle waveguide, based nanotube saturable absorber

We report passive mode-locking of an Er-doped fiber laser using carbon nanotubes deposited on the facet of a right-angle optical waveguide. © 2013 IEEE.

Evanescent-wave coupled right angled buried waveguide: Applications in carbon nanotube mode-locking

We present an evanescent-field device based on a right-angled waveguide. This consists of orthogonal waveguides, with their points of intersection lying along an angled facet of the chip. Light guided along one waveguide is incident at the angled dielectric-air facet at an angle exceeding the critical angle, so that the totally internally reflected light is coupled into the second waveguide. By depositing a nanotube film on the angled surface, the chip is then used to mode-lock an Erbium doped fiber ring laser with a repetition rate of 26 MHz, and pulse duration of 800 fs. © 2013 AIP Publishing LLC.