Announcements - fiber coating
One problem we had in the past was the mixing of solutions in the drop. The glucose drop is more viscous than pure water. When we add the silver solution to it, most of the time the solutions don't mix properly, and silver doesn't reach the surface of the optical fiber effectively. In order to improve this we need to mix the drop. One idea is to use a speaker to shake the drop during the coating process.
Work Party report (members only).
We modified our optical fiber we coating technique to coat the entire length of the fiber. The idea is to go from a drop to a grove filled with solutions, or even better, to coating within a glass capillary. See experimental notes. These preliminary results show that this process can be optimized.
pictures taken during the experiment
We are pleased to announce our last results on wet silver coating in a drop. A Mosquito was used to monitor the coating process in real time. The adjacent graph shows the time variation of the laser intensity reflected back from the mirror in formation, during the coating process (the data is inverted). The result is a "S" curve, showing a non-linear beginning of the coating process, a linear progression, which represents the increase in thickness of the silver layer, and a saturation regime.
These results demonstrate that we can render the deposition process automatic, with the possibility to preset the process to a given % of reflectivity/transmissivity. In other words, we can design a one-button coating machine.
See the experimental report.
photos from the last work party
We are planning another optical fiber coating work party for next week to produce a few joint-type transducers with a silver coated glass LEVER, for the Mosquito that is going to Royal Victoria Hospital, Mcgill University (to Dr. Sabah Hussein). Recently we have also started to work on a different type of transducer, the constriction type, which also requires optical fiber coating. We are planing to test the joint-type and the constriction type in the lab of Dr. Sabah Hussein.