High reflection isolation device

A high reflection isolation device comprising:

• a metal tube;
• a glass tube enclosed by the metal tube;
• a dual fiber pigtail having a first fiber and a second fiber, the dual fiber pigtail be enclosed by the glass tube;
• a GRIN lens attached to the metal tube and aligning with the dual fiber pigtail;
• and
• filter means for filtering unnecessary components respectively contained in an input light signal and a reflected light signal, and allowing light having a specific wavelength to pass through;
• wherein
• the input light signal and the reflected light signal are transmitted via the first fiber and the second fiber, respectively.

A high reflection isolation device assembly comprising:

• a ferrule with first and second fibers therein;
• a GRIN lens axially aligned with and spaced from the ferrule;
• a first filter for a first wavelength disposed on a distal end of the GRIN lens away from said ferrule;
• and
• a second filter for a second wavelength disposed between said GRIN lens and said ferrule;
• wherein
• said second filter does not block a light path coming from the first fiber, while the second filter essentially blocks another light path which is reflected from the first filter and is ready to enter the second fiber.