Miniature optical dispersion compensator with low insertion loss

An optical dispersion compensation system for a predetermined range of wavelengths, said system comprising:

• a first optical dispersion compensator comprising:
• a first Fabry-Perot etalon having a first front reflective mirror and a first rear reflective mirror in a parallel spaced relationship to form a first cavity with a first length between said first front reflective mirror and said first rear reflective mirror, the reflectivity of said first front reflective mirror being substantially smaller than the reflectivity of said first rear reflective mirror, said reflectivity of said first rear reflective mirror being greater than 97% and less than 100%, and
• a first dual-fiber collimator comprising a first dual-fiber pigtail and a first GRIN lens, said first dual-fiber pigtail having a first input fiber and a first output fiber with a first separation between said first input fiber and said first output fiber, and
• a second optical dispersion compensator comprising:
• a second Fabry-Perot etalon having a second front reflective mirror and a second rear reflective mirror in a parallel spaced relationship to form a second cavity with a second length between said second front reflective mirror and said second rear reflective mirror, the reflectivity of said second front reflective mirror being substantially smaller than the reflectivity of said second rear reflective mirror, said reflectivity of said second rear reflective mirror being greater than 97% and less than 100%, and
• a second dual-fiber collimator comprising a second dual-fiber pigtail and a second GRIN lens, said first dual-fiber pigtail having a second input fiber and a second output fiber with a second separation between said second input fiber and second output fiber,
• wherein an optical signal is coupled into said first input fiber and then collimated by said first GRIN lens into a first collimated incident beam which is incident on said first Fabry-Perot etalon with a first incident angle, said first collimated incident beam is reflected back by said first Fabry-Perot etalon into a first collimated reflected beam which is collected by said first GRIN lens and then coupled into said first output fiber, the optical signal from said first output fiber is further coupled into said second input fiber and then collimated by said second GRIN lens into a second collimated incident beam which is incident on said second Fabry-Perot etalon with a second incident angle, said second collimated incident beam is reflected back by said second Fabry-Perot etalon into a second collimated reflected beam which is collected by said second GRIN lens and then coupled into said second output fiber, such that at least one negative dispersion region is achieved.

A method of fabricating an optical dispersion compensator for a predetermined range of wavelengths, said method comprising:

• coating the front surface and the rear surface of a etalon into a front reflective mirror and a rear reflective mirror, the reflectivity of said front reflective mirror being substantially smaller than the reflectivity of said rear reflective mirror, said reflectivity of said rear reflective mirror being greater than 97% and less than 100%,
• fixating a GRIN lens with said etalon,
• choosing a dual-fiber pigtail having a input fiber and a output fiber with a separation between said input fiber and said output fiber,
• aligning said dual-fiber pigtail with said GRIN lens fixated with said etalon, and
• fixating said dual-fiber pigtail with said GRIN lens fixated with said etalon, such that that at least one negative dispersion region is achieved.