A theoretical modeling of continuous wave UV laser induced waveguides in congruent LiNbO
A side-pump coupler with a refractive index valley was investigated theoretically and experimentally. The high pump coupling efficiency and the suppression of backward light propagation due to the refractive index valley are illustrated. Based on the analysis, the
Tunable harmonic mode-locking of (HML) one kind of dissipative solitons (DSs) has been experimentally demonstrated in an Er-doped fiber (EDF) laser for the first time. The laser is mode-locked by nonlinear polarization rotation. The repetition rate can be tuned from the 2nd to 10th-order HML. A high repetition rate of 232 MHz (10th- order HML) has been observed in this laser, and the pulse duration after compression is 153-fs with single-pulse energy of 0.5 nJ. The spectral width of the pulses decreases as the harmonic order increases in the experiment, which is demonstrated for the first time, consistent with the numerical study. A rule based on monitoring the pulse spectral width to find desired-order HML is also proposed.
We propose and experimentally demonstrate a time-division-multiplexed acoustic sensor array employing multiple low-gain Er-doped fiber amplifiers to multiplex ten compact Fabry-Perot acoustic sensors. We show that the ten sensors can be interrogated with a single laser diode at a single wavelength, and exhibit the same measured SNR within
The generation and accumulation of random jitter (RJ) in channels using multimode fibers (MMF) and vertical cavity surface emitting lasers (VCSEL) is investigated. A novel theoretical model that accommodates mode partition noise (MPN) and modal-chromatic dispersion interaction (MCDI) for the length dependence of RJ in VCSEL-MMF channels is developed. The proposed model requires a few channel parameters such as length, MPN coefficient, spectral width of the source, and a new parameter for describing the modal-chromatic interaction. Simulation predictions are verified by experiments.
A metal insulator metal (MIM) waveguide structure which propagates a strongly confined sub-wavelength plasmon mode is proposed. In particular the structure permits electrical pumping of the waveguide core. The waveguide can in principle be fabricated with thin cores down to a few tens of nano meters wide. When quantum well material is employed, the waveguide core can be formed with self aligned quantum wire or quantum dot gain material. The performance of the proposed structure is compared to other plasmon mode and dielectric waveguide structures, and shown to provide significantly improved confinement of energy in the high index waveguide core. The implications of such waveguides when used as electrically pumped waveguides for optical amplifiers and nano-lasers is examined. It is shown that these electrically pumped waveguide structures offer the possibility of net modal gains in the region of 1900
While plasmonic nano-antennas can produce intense electric fields in a very small area, in general, these devices cannot handle high power, because of their small footprints. In order to increase the maximum peak power that these devices can withstand, they can be driven by nano-second pulses from a larger diameter
The authors give an overview of experimental results on 10.7 Gb/s over large-core 1 mm polymethyl-methacrylate (PMMA) polymer optical fiber (POF). The comparison starts with simple non-return-to-zero (NRZ) transmission without equalization. Next, measurement results with feed-forward-, decision -feedback equalization (FFE, DFE) and maximum likelihood sequence estimation (MLSE) are presented. Finally, experimental results with more advanced modulation schemes like pulse amplitude modulation (PAM) and discrete multitone (DMT) modulation are investigated. The experiments were carried out with a Vertical-Cavity Surface-Emitting Laser (VCSEL) at 0 dBm to comply with consumer eye-safety regulation or with a 10 mW laser diode (LD) that could be used in active optical cables.
We present a new model of the noise and drift induced by coherent backscattering in a fiber optic gyroscope (FOG) interrogated with a light source of arbitrary temporal coherence. This study is critical to understand whether a FOG driven with a laser instead of a broadband source can attain high sensitivity and stability, which would have the overwhelming benefit of improving the FOG scale factor stability by at least ten-fold and would enable the use of FOGs for inertial navigation of aircrafts. Analytical and numerical solutions bring to light two significant new predictions. First, coherent-backscattering noise can be made negligibly small by utilizing a laser with a very narrow linewidth (less than
We demonstrate that by driving a fiber optic gyroscope (FOG) with a laser of relatively broad linewidth (