Erbium-Doped Fiber Amplifiers
Chapter 3: Description
Page 4
TTN256521-D02
Description
Thorlabs’ EDFA300S and EDFA300P are core-pumped Erbium-doped fiber amplifiers that provide >40 dB small
signal gain and >300 mW saturated output power. The amplifiers are offered in a compact, turnkey benchtop
package with FC/APC input and output connectors and in two single-mode (SM) and polarization-maintaining (PM)
models. The EDFA300S SM (non-PM) amplifier is polarization-insensitive and input/output fibers to the amplifier
are standard single-mode fiber (SMF-28 Ultra). The EDFA300P PM amplifier is polarization sensitive, only
amplifying light that is linearly polarized along the slow axis. The input and output fibers of the PM amplifier are
polarization maintaining fiber (PM1550-XP) and the connector keys are aligned the slow axis of the fibers. The
EDFAs include precision current drivers to adjust the pump laser power in the amplifier. The current adjustment,
done through an adjustment knob on the front panel, varies the amplifier gain. The amplifier includes input and
output isolators to protect the input laser source from any amplified spontaneous emission or back reflections, as
well as to prevent the pump light from exiting the amplifier.
The EDFA gain can be controlled in constant current control (ACC) mode via the front panel interface. The pump
current of the amplifier is adjustable through the instrument's front panel, allowing the user to vary the gain and
output power. The display screen shows the pump level, as well as the temperature and emission status. An
indicator light is also included on the enable button to show when the internal laser is active. In addition to this mode
of operation, the EDFA can be operated in constant power control (APC) and constant gain control (AGC) modes
using a command-line interface via USB connection with a PC. These modes of operation allow the user to control
the amplifier for a fixed output power level or a fixed gain value. The amplifier automatically adjusts the pump current
in order to maintain the power or gain target values. For further information regarding all three modes of operation,
please see Chapter 5.
For added safety, there is an interlock connector located on the rear panel that must be shorted in order for the
output to be enabled. This can easily be configured to be triggered by doors to disable the fiber amplifier in unsafe
conditions. An enable button must be set to activate the amplifier, and a green LED indicator displays the current
state of the unit. There is a 3 second delay before the fiber amplifier turns on, and the user is warned by the rapidly
blinking LED.
The amplifier includes a universal power supply allowing operation over 100 to 240 VAC without the need for
selecting the line voltage. The fuse access is conveniently located on the rear panel.
3.1.
Shipping List
The EDFA300 units consist of the following components:
•
C-Band Erbium-Doped Fiber Amplifier in Benchtop Package
•
Interlock-Shorting BNC Connector
•
Region-Specific Power Cord
•
FBC250 Connector and Bulkhead Cleaner
•
1 m long FC/APC patch cables (P3-SMF28Y-FC-1 or P3-SMF28E-FC-1 for SM, P3-1550PMY-1 or P3-
1550PM-FC-1 for PM); please see section 4.4 for how to safely connect to the amplifier ports and minimize
the risk of connector damage.
•
Sacrificial fiber interface for connection to the output port (please see section 4.4).
