Optical fibers with improved bend performance and manufacturing method thereof

An optical fiber (100) comprising:

• a core region (108) defined by a core refractive index profile (200), wherein the core region (108) has a first core (102) defined by a first core refractive index (RI) profile (202) and a first core RI max (Δpeak) and a second core (104) defined by a second core RI profile (204) and a second core RI max (Δcore), wherein an absolute difference between the first core RI max (Δpeak) and the second core RI max (Δcore) is between 0.02 to 0.14, wherein the first core (102) has a first core alpha between 1 to 3 and the second core (108) has a second core alpha between 4 to 8;
• and
• a cladding region (106) surrounding the core region (108), wherein the cladding region (106) is defined by a cladding refractive index profile (400) and a cladding RI max (Δclad), wherein the cladding region (106) further comprising a first cladding (110), a second cladding (112) and a third cladding (114) such that the first cladding (110) and the third cladding (114) have pure silica and the second cladding (112) has down-doped silica, wherein the first core RI max (Δpeak) is greater than the second core RI max (Δcore) and the second core RI max (Δcore) is greater than the cladding RI max (Δclad),
• wherein the optical fiber (100) has a macro-bend loss of less than or equal to 0.03 dB per 10 turns at 15 mm radius and at 1550 nm wavelength and a macro-bend loss of less than or equal to 0.1 dB per 10 turns at 15 mm radius and at 1625 nm wavelength.