
Optical Fiber Communications 4th Edition by Gerd Keiser
ุงููุณุฎุฉ 4ุงูุฑูู ุงูู ุนูุงุฑู ุงูุฏููู: 978-0073380711
Optical Fiber Communications 4th Edition by Gerd Keiser
ุงููุณุฎุฉ 4ุงูุฑูู ุงูู ุนูุงุฑู ุงูุฏููู: 978-0073380711 ุชู
ุฑูู 27
A plane reflection grating can be used as a wavelength-division multiplexer when mounted as shown in Fig. 10.42. The angular properties of this grating are given by the grating equation
where is the grating period, k is the interference order, n is the refractive index of the medium between the lens and the grating, and and are the angles of the incident and reflected beams, respectively, measured normal to the grating.
( a ) Using the grating equation, show that the angular dispersion is given by
( b ) If the fractional beam spread S is given by
where m is the number of wavelength channels, find the upper limit on for beam spreading of less than 1 percent given that = 26 nm, = 1350 nm, and
m = 3
Fig. 10.42 Wavelength multiplexing with a reflection grating
where is the grating period, k is the interference order, n is the refractive index of the medium between the lens and the grating, and and are the angles of the incident and reflected beams, respectively, measured normal to the grating.
( a ) Using the grating equation, show that the angular dispersion is given by
( b ) If the fractional beam spread S is given by
where m is the number of wavelength channels, find the upper limit on for beam spreading of less than 1 percent given that = 26 nm, = 1350 nm, and
m = 3
Fig. 10.42 Wavelength multiplexing with a reflection grating
ุงูุชูุถูุญ
Optical Fiber Communications 4th Edition by Gerd Keiser
ูู ุงุฐุง ูู ูุนุฌุจู ูุฐุง ุงูุชู ุฑููุ
ุฃุฎุฑู 8 ุฃุญุฑู ูุญุฏ ุฃุฏูู ู 255 ุญุฑูุงู ูุญุฏ ุฃูุตู
ุญุฑู 255

