Fiber optic pigtail design for reducing insertion loss and insertion loss ripple

A system for reducing insertion loss and insertion ripple when coupling optical fiber to an optical component, the system comprising:

• a ferrule coupled to the optical component;
• an input optical fiber having a first optical axis and a first end inserted into the ferrule and configured for transmitting an optical signal to the optical component, the input optical fiber further having:
• a first section having a first diameter,
• a second section having a second diameter, wherein the first diameter is greater than the second diameter, and
• a third section having a first end with the first cross-sectional area and a second end with a second cross-sectional area, wherein the first cross-sectional area is greater than the second cross-sectional area, and the third section is tapered from the first end towards the second end;
• and
• an output optical fiber having a second optical axis and a first end inserted into the ferrule and configured for receiving the optical signal reflected from the optical component, the output optical fiber further having:
• a first section having a first diameter,
• a second section having a second diameter, wherein the first diameter is greater than the second diameter, and
• a third section having a first end with the first cross-sectional area and a second end with a second cross-sectional area, wherein the first cross-sectional area is greater than the second cross-sectional area, and the third section is tapered from the first end towards the second end, wherein the second end of the third section of the output optical fiber has a D-shaped cross-section.