Optical Fiber Communications 4th Edition by Gerd Keiser

Question

Optical Fiber Communications 4th Edition by Gerd Keiser

Edition 4ISBN: 978-0073380711

Optical Fiber Communications 4th Edition by Gerd Keiser

Edition 4ISBN: 978-0073380711

Exercise 6

For laser structures that have strong carrier confinement, the threshold current density for stimulated emission J th can to a good approximation be related to the lasing-threshold optical gain g th by g th = $For laser structures that have strong carrier confinement, the threshold current density for stimulated emission J th can to a good approximation be related to the lasing-threshold optical gain g th by g th = where is a constant that depends on the specific device construction. Consider a GaAs laser with an optical cavity of length 250 µ m and width 100 µ m. At the normal operating temperature, the gain factor = 21 × 10 -3 A/cm 3 and the effective absorption coefficient = 10 cm -1. ( a ) If the refractive index is 3.6, find the threshold current density and the threshold current I th. Assume the laser end faces are uncoated and the current is restricted to the optical cavity. ( b ) What is the threshold current if the laser cavity width is reduced to 10 µ m$ where $For laser structures that have strong carrier confinement, the threshold current density for stimulated emission J th can to a good approximation be related to the lasing-threshold optical gain g th by g th = where is a constant that depends on the specific device construction. Consider a GaAs laser with an optical cavity of length 250 µ m and width 100 µ m. At the normal operating temperature, the gain factor = 21 × 10 -3 A/cm 3 and the effective absorption coefficient = 10 cm -1. ( a ) If the refractive index is 3.6, find the threshold current density and the threshold current I th. Assume the laser end faces are uncoated and the current is restricted to the optical cavity. ( b ) What is the threshold current if the laser cavity width is reduced to 10 µ m$ is a constant that depends on the specific device construction. Consider a GaAs laser with an optical cavity of length 250 µ m and width 100 µ m. At the normal operating temperature, the gain factor $For laser structures that have strong carrier confinement, the threshold current density for stimulated emission J th can to a good approximation be related to the lasing-threshold optical gain g th by g th = where is a constant that depends on the specific device construction. Consider a GaAs laser with an optical cavity of length 250 µ m and width 100 µ m. At the normal operating temperature, the gain factor = 21 × 10 -3 A/cm 3 and the effective absorption coefficient = 10 cm -1. ( a ) If the refractive index is 3.6, find the threshold current density and the threshold current I th. Assume the laser end faces are uncoated and the current is restricted to the optical cavity. ( b ) What is the threshold current if the laser cavity width is reduced to 10 µ m$ = 21 × 10 -3 A/cm 3 and the effective absorption coefficient = 10 cm -1.
( a ) If the refractive index is 3.6, find the threshold current density and the threshold current I th. Assume the laser end faces are uncoated and the current is restricted to the optical cavity.
( b ) What is the threshold current if the laser cavity width is reduced to 10 µ m

Explanation

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(a)
Write the expression of the Fresnel ...