NuAmp CW Fiber Amplifiers
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□ sa BE Progress on High Power Single Frequency Fiber Amplifiers at 1|mm, 1.5mm and 2|mm www.nufern.com

Examples of Single Frequency Platforms at and 1.5mm and Applications

Single Frequency PM Amplifier Platform (2-15W) 5 700 600 500 400 300 200 10 ^4 0 «■►♦ ♦ ♦ ♦ ♦ ♦ 0 5 10 15 20 25 Output Power (W) SBS threshold at 1064nm in 6.5m PLMA-YDF-10125 with 3m PM-DSF-10/125 delivery fiber on output \v flUFERN

Single Frequency PM Amplifier Platform (2-15W) 5 700 600 500 400 300 200 10 ^4 0 «■►♦ ♦ ♦ ♦ ♦ ♦ 0 5 10 15 20 25 Output Power (W) Practical SBS limit in current gnration of PM single mode Yb and Er:Yb multi-stage amplifiers is ~20W (15W) at 1jim (1.5jim) X~\ tlUFERN

Single Frequency PM Amplifier Platform (2-15W) 5 700 600 500 400 300 200 100 ♦ ♦ 0 5 10 15 20 25 Output Power (W) Multiple options available (isolation, control, input power, etc)

Single Frequency PM Amplifier Platform (2-15W) 5 700 600 500 400 300 200 10 ^4 0 «■►♦ ♦ ♦ ♦ ♦ ♦ 0 5 10 15 20 25 Output Power (W) Mature platform, more than 50 amplifiers delivered over last 4 years

Single Frequency PM Amplifier Platform (2-15W) Specially designed Yb doped fibers with increased mode filed diameter but maintaining single mode spatial beam profile were used to alleviate the SBS limitation.

Single Frequency PM Amplifier Platform (2-15W) SBS-suppression fibers were used to further decrease the SBS threshold.

Single Frequency PM Amplifier Platform (2-15W) Optical Specifications NUA-UUUU-PV-0002-YZ NUA-UUUU-PV-0005-YZ Optical Spcification1 Output Power 2.0 W 5.0 W Output Power Adjustment (nominal) 10-100% 10-100% Power Stabi lity2 < 3.0% * 3.0% M Dde TEMa 黙DD Output Type No isolator, FC/APC connector No isolator, FC/APC connector Fiberto fiber Isolator, Fiberto fiber Isolator, FC/APC connector FC/APC connector Fiberto free space isolator Fiber to free space isolator In put Type FC/APC bulkhead FC/APC bulkhead Mode of Opration CW CW Polarisation Linear Linear PER at Rated Power3 > 15 dB &15dB...

Single Frequency PM Amplifier Platform (2-15W) Mechanical, Electrical &Environmental Specifications 1 AU specifications are at RI and proper heasmking is required. 'l Stabiiity is measured over 2-hour period & caicuiaed using (max-min)/Avg. 3 Measured with isoiator 4Custom OEM packaging avaifabie on reues t. qUFERN

Single Frequency PM Amplifier Platform (40W at 1mm) By adopting state of the art PM LMA (25/400) fibers the SBS threshold can be raised to >40W (at 1 mm) with 5kHz seed source 80 > 70 o 60 i 50 0 Cl 40 « 30 O * 4 20 M O 10 m -20/400 ■25/400 1 80 0 M 0 20 40 60 Amplifier Output Power (W) ([UFERN

Single Frequency PM Amplifier Platform (100W at 1mm) Practical SBS limit is increased in these PM LMA based amplifiers by using a temprature gradient along the active fiber length ^ 4UFERN

Single Frequency PM Amplifier Platform (100W at 1mm) Temprature gradient shifts the local SBS gain spectrum along the fiber length flUFERN

Single Frequency PM Amplifier Platform (100W at 1mm) Amp Measured Parameters Property Tested Value Output Power [~5kHz] 105.5 W PER >15.5 dB M2 <1.10 Wavelength 1064.4 nm Input Power ~ 33mW Max Backward Power < 25mW QUFERN

Single Frequency PM Amplifier Platform (100W at 1mm) POWER with Oven Off Isa [A] Isb [A] PSIGNAL [W] Pback [mW] 10 10.4 0.25 20 33.0 0.55 30 61.1 23.0

Single Frequency PM Amplifier Platform (100W at 1mm) Beam Propagation Factor 100W Mx2 = 1.08 MY2 = 1.09 qUFERN

SBS Threshold Dpends on Linewidth of Seed Source SBS Threshold vs. Linewidth 800 700 600 500 JE 400 CL 300 200 100 0 0 1 234 Linewidth [GHz] 5 6 In some applications 1-10GHz linewidth is suitable (this signal linewidth reduces the SBS gain in the amplifier, which has linewidth ~50MHz) V

SBS Threshold Dpends on Linewidth of Seed Source SBS Threshold vs. Linewidth 800 700 600 500 JE 400 CL 300 200 100 0 0 1 234 Linewidth [GHz] 5 6 In those cases broadening the linewidth to achieve more output power is an acceptable compromise V

SBS Threshold Dpends on Linewidth Seed Source SBS Threshold vs. Linewidth Linewidth [GHz] this case LMA fibers generate output power >1kW CW

■ ■ ■ ■ (3GHz seed s 1 kW Amplifier 1000 800 a." 600 400 200 0 0 200 400 600 800 1000 1200 "launched pump [w] " 330mm j 390mm~ M2 = 1.1 Measured at 1 kW Multi-stage turn-key packed amplifier (1mW input power) qUFERN

■ ■ ■ ■ (3GHz seed s 1 kW Amplifier 1000 800 a." 600 400 200 0 0 200 400 600 800 1000 1200 "launched pump [w] " 330mm j 390mm~ M2 = 1.1 Measured at 1 kW Linearly polarized option PER~13dB qUFERN

■ ■ ■ ■ (3GHz seed s 1 kW Amplifier 1000 800 a." 600 400 200 0 0 200 400 600 800 1000 1200 "launched pump [w] " 330mm j 390mm~ M2 = 1.1 Measured at 1 kW Multiple units shipped 2008-2009 qUFERN

High Power Single Frequency 1.5mm PM-LMA Amp PLMA-EYDF-25/300 Dichroic filters 300W 940nm bar diode ; 1060nm ASE 1550nm signal 50mW 1550nm single-frequency seed fiber laser, 5kHz linewidth qUFERN

High Power Single Frequency 1.5mm PM-LMA Amp PLMA-EYDF-25/300 Dichroic filters 300W 940nm bar diode ; 1060nm ASE 1550nm signal 10W PM single-frequency pre-amp (NuAMP) qUFERN

High Power Single Frequency 1.5mm PM-LMA Amp PLMA-EYDF-25/300 Dichroic filters 300W 940nm bar diode ; 1060nm ASE 1550nm signal Amplified in Er:Yb PM LMA 25/300 fiber, counter pumped at 940nm qUFERN

Rcent Advances in Tm-fibers for 2 m m Wavelength

Pump Options forTm-doped Fibers O o d> </) tfl o o ã O "55 LU ˣ O ■Emission Absorption Gain Spectral Rթgion O (0 < 700 1200 1700 Wavelength (nm) 2200 Rsonant pumping around 1560nm is difficult to power scale with direct diode pumping (no high power/brightness pumps) QUFERN

Pump Options forTm-doped Fibers O o d> </) tfl o o ã O "55 LU O ■Emission ■Absorption Gain Spectral R룩gion O < 700 1200 1700 Wavelength (nm) 2200 Solution here is to pump with Er:Yb fiber laser which is in turn pumped by 9xx high brightness diodes (>400W output power demonstrated, IPG 2007) QUFERN