Abstract: An apparatus for manual transfer of a viscous fluid such as essential oil or wax comprises a tip having a depression to accommodate an amount of the viscous fluid and a brim to cause a break in a vapor trail when the amount of viscous fluid is being placed on a heated surface and becomes vaporized; a cap that fits over the tip to prevent unwanted transfer of any remaining viscous fluid to surroundings when the tool resting on a surface; and a handle to allow a user to hold the without contacting the tip.

Abstract: A self-mixing sensor usable for remotely measuring speed, vibrations, range, and length is provided in a manner making the device practical for economic implementation while retaining accuracy. In one embodiment, the device is configured to avoid mode hopping, such as by providing for relatively high loss for all modes other than the desired mode. Preferably this is accomplished by utilizing laser types that have a high degree of side mode supression, such as DFB lasers or through active or passive control of the amount of light permitted to reenter the laser.