Introduction

FiberLabs’ PDFAs have been a popular choice for amplifying 100G/400G Ethernet signal in the O-band, particularly useful for transceiver testing (see example), as well as network monitoring and reach extension. Currently our high-end model is FL-AMP8611-OB-20, and we always hear strong demands for a higher output power.

We are now ready to unvail a “prototype” of our higher-power PDFA FL-AMP8612-OB, targeting to double the output power. This post provides basic amplification characteristics of the prototype.

Amplification characteristics at 1310 nm

The setup of the experiment is shown in the above picture. The input signal (0 dBm at 1310 nm) was provided by FiberLabs TLS-FL-O tunable laser. The input signal was amplified in the prototype amplifier, and the output signal was measured by a power meter and optical spectrum analyzer. The size of the amplifier chassis is the same as FL-AMP8611-OB20.

The graph shown in below is the measured output power with regard to the pump current (normalized to maximum available). This prototype amplifier provided maxium 350 mW (>25 dBm), which is limited by available pump power.

The output spectra (at +23- and +25-dBm output power) are shown below. The amplifier provided a clean spectrum with no onset of unstable behavior.

Next step

We are excited to get an output power much higher than our 23-dBm target, however, this is a preliminary result and additional tests should be done before product release.

We plan to start more thorough testing – for example, gain measurement at 400GBASE-LR8/ER8 and CWDM4 wavelengths. This amplifier should provide a higher gain at these wavelengths, and thus it may allow us to produce a flat-gain O-band amplifier with the incorporation of a gain-flattening filter inside.

We appreciate your input!

If you are a potential customer interested in using this amplifier, we appreciate your input in order to make our product better. Please send us your requests via request sheet!