Opto-Electronics III
Assessment 1 Answers
Year 2025
0027 63 985 5033
,
, 1.1 Given
Core refractive index n1 = 1.5
Cladding refractive index n2 = 1.45
𝑛2
𝐶𝑟𝑖𝑡𝑖𝑐𝑎𝑙 𝑎𝑛𝑔𝑙𝑒 𝜃𝑐 = 𝑠𝑖𝑛−1 ( )
𝑛1
1.45
= 𝑠𝑖𝑛−1 ( )
1.5
= 75.20
𝑁𝑢𝑚𝑒𝑟𝑖𝑐𝑎𝑙 𝑎𝑝𝑒𝑟𝑡𝑢𝑟𝑒 𝑁𝐴 = √𝑛12 − 𝑛22
= √(1.5)2 − (1.45)2
= 0.384
𝐴𝑐𝑐𝑒𝑝𝑡𝑎𝑛𝑐𝑒 𝑎𝑛𝑔𝑙𝑒 𝜃𝑎 = 𝑠𝑖𝑛−1 (𝑁𝐴)
= 𝑠𝑖𝑛−1 (0.384)
= 22.60
Assessment 1 Answers
Year 2025
0027 63 985 5033
,
, 1.1 Given
Core refractive index n1 = 1.5
Cladding refractive index n2 = 1.45
𝑛2
𝐶𝑟𝑖𝑡𝑖𝑐𝑎𝑙 𝑎𝑛𝑔𝑙𝑒 𝜃𝑐 = 𝑠𝑖𝑛−1 ( )
𝑛1
1.45
= 𝑠𝑖𝑛−1 ( )
1.5
= 75.20
𝑁𝑢𝑚𝑒𝑟𝑖𝑐𝑎𝑙 𝑎𝑝𝑒𝑟𝑡𝑢𝑟𝑒 𝑁𝐴 = √𝑛12 − 𝑛22
= √(1.5)2 − (1.45)2
= 0.384
𝐴𝑐𝑐𝑒𝑝𝑡𝑎𝑛𝑐𝑒 𝑎𝑛𝑔𝑙𝑒 𝜃𝑎 = 𝑠𝑖𝑛−1 (𝑁𝐴)
= 𝑠𝑖𝑛−1 (0.384)
= 22.60
