Selectable filter module for optical fiber transmission system, and method of filtering light

An optical fiber system comprising:

• a wavelength division multiplexed optical fiber light transmission system having a light path therethrough;
• and
• a filter module positioned to controllably place a light filter into the light path of the optical fiber light transmission system and remove the light filter from the light path, the filter module comprising
• a movable support on which a plurality of light filters is mounted, and
• a drive mechanism operably connected to the movable support to controllably move the light filters individually into and out of the light path, wherein the drive mechanism comprises
• a lead screw drivably connected to the movable support, and
• a stepper motor driving the lead screw.

A method for filtering light signals, comprising the steps of

• furnishing an optical fiber light transmission system having a light path therethrough;
• positioning a filter module to controllably place a light filter into the light path of the optical fiber light transmission system and remove the light filter from the light path, the filter module comprising
• a movable support on which at least one light filter is mounted, and
• a drive mechanism operably connected to the movable support to controllably move the at least one light filter into and out of the light path;
• and
• operating the drive mechanism to controllably place the light filter into the light path and controllably remove the light filter from the light path.