Integrated Optics - Applied Optics Fundamentals and Device Applications - page 274

RF in

I O

I in

I out (V)

2Z M 2Z M

Schematic of traveling wave interferometer

dc to 10 GHz
4-11 V drive voltages
850, 1300, or 1550 nm

FIGURE 5.36
Traveling-wave intensity modulator. (Courtesy of Crystal Technology, A Siemans Company,
Palo Alto, CA.)

50 Ω terminating
resistor

Modulation
input

Optical input

Optical output

Fiber pigtailed
Operation to 15 GHz
Wide range of wavelengths (0.4-1.6 µm)

FIGURE 5.37
KTP Mach-Zehnder modulator.

• Excess loss—the amount of optical power lost in a device, in addi-
tion to the insertion loss.
• Passband—the wavelengths at which the performance specifications
apply. Splitters are generally highly wavelength sensitive.
• Directivity—the amount of power reflected relative to the input
power to a device, measured exiting an input fiber. FBTs typically
exhibit better than 60 dB directivity.
• Isolation—when a splitter is used as a demultiplexer, isolation is a
measure of the coupler's ability to separate two or more wavelengths.
Isolation is usually measured as a dB difference in the measured
optical power of one wavelength compared to another.