Building a Continuous Wave

Erbium Doped Fiber Laser and Amplifier

Ben BakerKristen Norton

What is a fiber laser?• Why should we care?

• communications!! • long-ranges• amplify light in 1.5-μm region = where telecom fibers

have loss min

• requirements• gain medium = fiber with erbium ions (Er3+)

• heavy doping• CW

• pump• signal/feedback

Erbium absorption/emission

http://www.fibercore.com/Fiberpaedia/tabid/84/agentType/View/PropertyID/137/Default.aspx

Emission Spectrum

• depends on • how broad energy levels are• proximity of other Er ions• diode lasers vs fiber lasers• spontaneous emission

vs feedback & gain

EDFL• 980 nm diode laser

• APC connectors

• wavelength division multiplexer

• fusion splicing

• erbium fiber

• removing pump photons

• output coupler varies feedback

• measure output power

• attenuator varies feedback

• optical isolator prevents unwanted feedback

EDFA• no feedback, amplifying

another signal

• measure all output power

Comparing Goals

• Characterize EDFL• pump power vs output power• emission spectrum

• Characterize EDFA• gain = signal power vs output power• amplification of continuous wave & pulse• emission spectra

• spontaneous emission• amplified signal

How??• Power meter, oscilloscopes

• Monochromator, diffraction grating

http://www.sciencetech-inc.com/catalog/13/monochromators/9030

Loop power

Loop power

Output power

Output power

signal = all fiber pulsed EDFL

signal = all fiber pulsed EDFL

signal = Jared and Wesley’s soliton EDFL

signal = Jared and Wesley’s soliton EDFL