Optical fiber with gratings and methods of forming thereof

An optical fiber comprising:

• a core region having a plurality of optical gratings within the core
• a cladding region surrounding the core region, wherein the core and cladding have a combined outer diameter of 100 μm to 125 μm;
• and
• a coating surrounding the cladding region, wherein the coating has a thickness of less than or equal to 20 μm, and wherein the coating comprises one of:
• (i) a high-modulus coating layer surrounding the cladding region, wherein the high-modulus coating layer has a Young's modulus of greater than or equal to 0.5 GPa;
• or (ii) a low-modulus coating layer surrounding the cladding region and a high-modulus coating layer surrounding the low-modulus coating layer, wherein the low-modulus coating layer has a Young's modulus of less than or equal to 5 MPa and the high-modulus coating layer has a Young's modulus of greater than or equal to 0.5 GPa.

An optical sensing system, comprising:

• a control system comprising a light source, a light detector, and a processor;
• an optical fiber;
• and
• a light transmitting member operably coupling the optical fiber to the control system, wherein the optical fiber comprises:
• a core region having a plurality of optical gratings within the core;
• a cladding region surrounding the core region, wherein the core and cladding have a combined outer diameter of 100 μm to 125 μm;
• and
• a coating surrounding the cladding region, wherein the coating has a thickness of less than or equal to 20 μm, and wherein the coating comprises one of:
• (i) a high-modulus coating layer surrounding the cladding region, wherein the high-modulus coating layer has a Young's modulus of greater than or equal to 0.5 GPa;
• or (ii) a low-modulus coating layer surrounding the cladding region and a high-modulus coating layer surrounding the low-modulus coating layer, wherein the low-modulus coating layer has a Young's modulus of less than or equal to 5 MPa and the high-modulus coating layer has a Young's modulus of greater than or equal to 0.5 GPa.