10G bit/s Small, High-performance Receiver Module for

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10G bit/s Small,
High-performance Receiver Module
for Optical Communications
The high-sensitivity/broad band receiver module consists of an avalanche
photodiode (APD) and preamplifier IC in a small package. It is designed for use in
10G bit/s optical communication systems.
Product Description
Product Features
With the ongoing expansion of the Internet and consequent
increase in data traffic, the demand for high-density, highspeed optical communication is on the increase. Transmission
bit rates of up to 10G bit/s have been put into practical use,
and the receiver modules to be used in the optical communication need to meet ever stricter demands for high-speed
operation, high-quality transmission properties, miniaturization, high reliability, and low price. To address these
demands, FUJITSU has commercialized the FRM5N141GW,
a 10G bit/s receiver module that integrates an avalanche
photodiode (APD) and preamplifier IC into just a single small
Among its other features, the product incorporates an
avalanche photodiode that converts/amplifies optical signal
into current signal, a preamplifier IC that converts/ amplifies
current signal into voltage signal, an optical system to
condense the signal from fiber, and a thermistor to monitor
the package temperature-all within a package volume of
only 0.25cc.
■ Small package (only 0.25cc in volume)
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■ Coplanar-type differential output
■ Operating case temperature range: 5
to 75
■ Operating wavelength range: 1270nm to 1620nm
Photo 1 External View
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■ Minimum sensitivity: 24dBm or smaller
■ Overload: 7dBm or larger
Fig. 1 shows the outline drawing of this product. The package
volume is 0.25cc, and the lead functioning as the electrical
interface is placed on one end of the package. These design
features reduce the mounting space to less than half that of
conventional receiver modules.
Table 1 shows the absolute maximum rating, and Table 2
shows the specifications of electrical and optical properties.
Fig. 2 shows the frequency response. According to this figure, a
wide bandwidth of 10GHz or larger is obtained when the
■ Bandwidth: 8.5GHz or larger
■ Built-in thermistor for temperature monitoring
■ High reliability compliant with Telcodia GR-468-CORE
Figure 1 Outline Drawing
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Table 1 Absolute Maximum Rating
APD multiplication factor is in the range of 3 to 9, enabling
support for FEC (Forward Error Correction) of 10.7G bit/sec
or 12.5G bit/s.
Fig. 3 shows the group delay. A flat group delay of 40ps or
smaller is obtained within the bandwidth, leading to output
waveform without distortion.
Fig. 4 shows the minimum sensitivity. Under the conditions of a 10G bit/s transmission rate and 10 12 error rate, a
minimum sensitivity of 26dBm or smaller has been achieved.
Table 2 Specifications of Electrical/Optical Characteristics
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Figure 2 Frequency Response
Figure 3 Group Delay
Figure 4 Minimum Sensitivity
Figure 5 Output Waveforms
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Figure 6 Output Amplitude
Figure 7 APD Responsivity
Fig. 5 shows the output waveforms of a small input signal
and large input signal. Favorable EYE opening is achieved
in both cases.
Fig. 6 shows the output amplitude of the preamplifier.
When a small signal is input, it operates linearly with 1.3k
transimpedance. When a large signal is input, output
amplitude is limited to 600mVp-p.
Fig. 7 shows APD responsivity in a long wavelength range.
A responsivity of 0.7A/W is obtained with an optical wavelength of 1620nm. This makes the FRM5N141GW optimal as
a receiver module for DWDM (Dense Wavelength Division
Multiplexing) transmission.
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Future Development
In the future, we plan to commercialize a high-gain receiver
module with a transimpedance four times higher than this
product and a low-power consumption receiver module with
a power supply voltage of 3.3V.