ADTRAN 1200218L1, User Manual

Page: 31 / 122

Chapter 2. Installation and Operation
61200663L1-1 OSU 300 User Manual 2-7
Optical Interface Port
The OSU 300 optical interface port consists of a single-mode or
multi-mode transceiver module composed of a transmitter, a
receiver, and an SC or ST receptacle. The optical interface port
supports angled SC type optical connectors (61200663L1 and L2
only) and operates in the 1280 nm to 1335 nm wavelength range
(1310 nm nominal). The total output power is 8 mW with a 50 mm
aperture at 10 cm distance, as defined by IEC. The optical interface
uses two fibers, one for each direction of transmission.
The transceiver optical power budgets for the optical transceivers
are 28dB (single-mode) and 9dB (multi-mode). These budgets are
calculated as follows:
Single-Mode
Worst case optical transmit power = -5dBm
Worst case optical receiver sensitivity = -34dBm
Calculations :
(34 - 5) dB = 29 dB - 1dB (optical path penalty) = 28dB
Multi-Mode
Worst case optical transmit power = -20dBm
Worst case optical receiver sensitivity = -30dBm
Calculations :
(30 - 20) dB = 10dB - 1dB (optical path penalty) = 9dB
The optical interface complies with the physical interface
parameters listed in ITU-T recommendation G 957, with IEC Class
1 laser safety requirements (under normal operating conditions)
and with FDA Class 1 laser safety requirements. The OSU 300
contains an integrated automatic shutdown circuit that disables the
laser when it detects transmitter failures, thus the Class 1 rating.
The FITS rating of the internal shutdown circuit is less than 500
FITS.