TY - JOUR
T1 - Monitoring of power coupling efficiency into fibre-optic beam delivery systems. Cladding power measurement techniques
AU - Boechat, Alvaro A P
AU - Su, Daoning
AU - Jones, Julian D C
PY - 1991/11
Y1 - 1991/11
N2 - In high-power fibre-optic beam delivery systems using Nd: YAG lasers, it is vital that power is coupled into the fibre core with very high efficiency, in order to avoid damage to the fibre, its cable and the beam delivery optics. We have shown that by measuring the optical power propagating in the cladding of the fibre, it is possible to monitor the coupling efficiency with much greater sensitivity than is available when the core-guided power is measured. We have developed a theory describing the power in the cladding of the fibre as a function of the launching conditions for a number of types of beam misalignment, and hence as a function of coupling efficiency. We have constructed and evaluated an optical device for monitoring cladding power, and conducted experiments which have validated our theoretical model. We have noted the implications of the cladding power monitoring device in the measurement of coupling efficiency, and have indicated other potential applications for fibre-optic beam delivery systems.
AB - In high-power fibre-optic beam delivery systems using Nd: YAG lasers, it is vital that power is coupled into the fibre core with very high efficiency, in order to avoid damage to the fibre, its cable and the beam delivery optics. We have shown that by measuring the optical power propagating in the cladding of the fibre, it is possible to monitor the coupling efficiency with much greater sensitivity than is available when the core-guided power is measured. We have developed a theory describing the power in the cladding of the fibre as a function of the launching conditions for a number of types of beam misalignment, and hence as a function of coupling efficiency. We have constructed and evaluated an optical device for monitoring cladding power, and conducted experiments which have validated our theoretical model. We have noted the implications of the cladding power monitoring device in the measurement of coupling efficiency, and have indicated other potential applications for fibre-optic beam delivery systems.
UR - http://www.scopus.com/inward/record.url?scp=0026253767&partnerID=8YFLogxK
U2 - 10.1088/0957-0233/2/11/019
DO - 10.1088/0957-0233/2/11/019
M3 - Article
SN - 0957-0233
VL - 2
SP - 1107
EP - 1112
JO - Measurement Science and Technology
JF - Measurement Science and Technology
IS - 11
ER -