{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

2004 EE 164 Problem Set 3 Solution

# 2004 EE 164 Problem Set 3 Solution - EE 164 Problem 1...

This preview shows pages 1–3. Sign up to view the full content.

EE 164 Problem Set 3 Spring 2004 Problem 1 An LED device composed of GaAlP semiconductor material is emitting at a wavelength of 650nm. Calculate the bandgap energy for the above material. Since , solving for c g g hc E E λ = ( ) ( ) 34 17 19 6.63 10 3 10 3.09 10 650 g c Js nm s hc E J nm λ × × = = = × In eV, ( ) 19 19 3.09 10 1.91 1.6 10 g eV J E eV C × = = × 1.91 g E eV = Problem 2: If an optical source coupled to a fiber is forward biased with a biasing voltage of 1.75 V will generate a forward current of 24 mV . Assuming diode internal efficiency of 1.5% and coupling angle of 30 ° . a) Find the coupling efficiency. Power input to the source, 24 1.75 42 in F F P I V mA V mW = × = × = 42 in P mW = Power output of the optical source, int o in P P η = int 0.015 42 0.63 o in P P mW mW η = × = × = 0.63 o P mW =

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
b) Calculate the optical power coupled into the fiber. The power output of the optical source becomes the optical power at the input of the fiber ( ) 0 in F P P = Efficiency, ( ) 2 c NA η = ( ) sin 30 0.5 NA = ° = ( ) ( ) 2 2 0.5 0.25 c NA η = = = 0.25 c η = Power coupled into the fiber, 0.25 0.63 157 F c in P P mW W η µ = × = × =
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}