6
AC component at the output of an AC-coupled high-speed
transimpedance amplifier. The gain of the DC path is set
equal to that of the AC path and temperature
compensated so that extinction ratios may be accurately
measured.
Photodetectors (Unamplified Photodiodes)
Frequency Domain Optimized
Applications that rely on transmitting signals at RF and
microwave frequencies benefit from detectors with flat
frequency responses and improved response at higher
frequencies. These applications include linear fiber-optic
transmission to and from remote antennas for
communication satellites, wireless cellular networks, and
cable television. Since the time-domain response is not
critical in these applications, the impulse response can
have ringing. In particular, Models 1414 and 1014
detectors are frequency domain optimized to provide
especially flat frequency responses over wide bandwidths.
Time Domain Optimized
If you need accurate reproduction of your signal in the
time domain, choose Model 1444 or 1024 time-domain-
optimized detectors. These models provide clean, fast
impulse responses with minimal ringing, and are ideal for
pulse measurements with digital high-speed
oscilloscopes. Moreover, they can be used in digital
communications applications, where spurious ringing can
degrade eye diagrams and the bit-error-rate (BER)
measurement of your system. And, because these
detectors are internally terminated at 50 , you won’t have
to worry about any reflections between the detector and
filter for standardized BER testing with SDH and SONET
filters.
Internal 9-V Battery
Models 1414, 1014, 1444, and 1024 combine an internal
9-V battery with the bias circuitry which make these
self-contained, eliminating the need for an external power
supply and reducing the possibility of photodiode damage
due to overvoltage.
