Compact Blue Green Lasers ppt.pdf

7/27/2019 Compact Blue Green Lasers ppt.pdf

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GREEN LASER-DIODE-PUMPEDERBIUM FIBER LASER

David Piehler and Dawn CravenApplied Photonics Division

Uniphase CorporationSan Jose, CaliforniaNorman Kwongartel Corporation

Alhambra, California

presented at Compact Blue/Green LasersSalt Lake City, UtahFriday, 11 February 1994paper CFA2


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Room-temperature visible upconversion fiber lasers inrare-earth-doped fluoride glass

Dopant ion

Holmium

Laser wavelengths(nm)550

Pump wavelengths(nm)645,750,890

[ E r b 1 ~ ~ : : : : :: :::: :::: ::::: ::::::: ::::::::::::::: :::::$45: ::::::::::::::: ::: : : : : : : : : : : : : : : : - - 8 0 ( f : ~ 7 Q :::: IPraseodymium 490,520,540,605 or 635 840 + 1020Thulium 480 1120


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Energy leyels of Er3+ in fluoride glass(including room-temperature lifetimes)544 nmESA ~ --6__- - - -

- - -A-j ------;/--t------ - - ; ; ; ; ~ = ; p ; ; ) - - ; ; ; ; ; ; ; ~ ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; =- '::-j!J:971 nm pump- - + - - ~ - - - ~ - - - - - - - -

- - ~ ) ~ - - - - - . ~ - ____.-______

4F 5/2J 801 nm pump4F 712

" !Hl1l253/2801 nm pump 4F9/2

4/9/24/11/2

971 nm pump 544 nm, ~ I a s e r 801 nm pump4/15/2

(0.45 ms)(0.12 ms)(7 ms)(9 ms)


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Population dynamicsRate equation model of 100 mW of 970 nm incident on an Er fiber

with core of 2 Jlm

c 0.5o~ 0.4::Ja.o0.. 0.3coc.Q 0.2t5LL 0.1

5 10 15time after turn-on (ms)

The long lived 4113/2 level acts as an excitation sink


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Fiber

Pump

The erbium fiber laserlength:material:dopant:core diameter:cutoff wavelength:numerical aperture:Ti :sapphire laserorInGaAs laser diodeOrtel Corporation

2.2 mfluorozirconate glass (Le Verre Fluore)1000 ppm Er3+2 Jlm800 nm0.31

EDFA pump module in 14-pin butterfly packagepigtailed to Flexcore 1060 fiber


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Ti:sapph ,re laser pumping

outputcoyplermUTor

..Q) 16.014.012.0

:; ~ 10.00.3:'5 E 8. 0o _ 6. 0

oa.

0.0

Er fiber lasel- - -R=

23 %

20.0 40.0 60.0 80.0

using an external mirror cavity launched 970 nm power (mW)

Er fiber laser --0---- R = 90% with.. lasingQ)

60.00 ~ R = 23% witha. ...... lasing-03: 40.0Q) Ec.. - 20.0 .................... - .:8--0.- ----0--- R = 90% without0f/) _ ~ i r - ~ . lasing.c 0. 0S .

0. 0 20.0 40.0 60.0 , 80.0 --- . . --- R = 23% withoutlaunched 970 nm power (mW) lasing


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971 nm Ti:sapphire pumping resultsWith an R = 23% @ 544 nm output coupler:

Threshold: 31 mW (with respect to coupled power) Slope efficiency: 51 % (w.r.t.c.p.)

l ~ 1_ mW of green laser light generated from 59 mW of coupled power -9 nm pump acceptance bandwidth (FWHM) centered at 971 nm (R=90% ;

25 mW launched)

this work:BT 1993:CNET 1992:BT 1991:

Ti:sa20 ...

...--.. BT 1993 ~ this work.s 15 (971 ~ ) (971 nm) ..."- ' ;CNET 1992 00) &. . . . (971 nm) 0~ 10 &. 0Q) .&.. ...CJ) ... 0u .& . BT 1991c ...Q) 5 &. ... 0 (801 nm)Q) 0"- .& . ...">

..."00 100 200 300 400

launched pump power (mW)2 )lm core, 0.31 NA3 )lm core, 0.20 NA (Brierley, et al., BT Tech. J. 11, 128 (1993))5.5 )lm core 0.18 NA (Allain, et al., Electron. Lett. 28 111 (1992))3.4)lm core, 0.18 NA (Whitley, et al., Electron Lett. 27 185 (1991))


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EDFAlaser diodepump module971 nm

Laser diode pumpingmode-matchinglenses

fiber pigtail

erbium dopedfluoride fiber

highreflectormUTor

. coupling efficiency is about 50%

544nm


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r.:-.:. . . : ,, I11II i ~ p! ' 1 I I I!,! I ij,lI j'n! llH- ;t t 1 ~ Jlti II I ' ~ l l . U . l . 9 l l ! . . L . L 8 o n m ! . . L l . . ! . . L L a s ~ 9 r" '---"!.I ..:..!..!.!.1!.!.!.!J..1 l..I.ll.1.! I I Il1jl tilll\l! iiI! Ifl1

-'ill : tllii 11I1: -J l l l l l l l l l l l l l l l l l f l lTl l fnnnnrn P I " ""u" .. I ! !l1[t nIT1.11 t t t t tHtHtt l t l t TEC : t r(+) .. , Ii ." 1 dillIliii il ~ o ~ 1 0 ~ f ; ~ ' : L D ( ~ L G , o ' " d . WiU

u 6 : I "TI 11111! I \ 0 ,', L O ~ ' ~ ; " G ' O ' " d 11 IIttl mH 1+tlt t tHWHtt l "' 11 nlermlslor I'; 12 NC j Itt,i IiI 13 NC I ./ '1I 14 TE Cooler(.)+0 - It i! ! . . . I : - - - ' - - ' - - < ' : " : : ' ~ - ' - - - - - - l I II~ t 1 ~ 1 111111111111111 1-11111111111111111 111111111111111 1111111111111111111 11111111111111111111111111111111111111 . . II II.,. I 111111111111 1 1 - I - I 1 I 1 + 1 1 I 1 1 ~ l n H ~ I H " I l m " H H ~ I J U H U + I H l + J . i ~ I - H I l I U + l f l . l 1 I 1 J 1 1 1 1 I H 111"111111i \; TIl'""!~ inl!j I

. , I-II' - '\ I; , ii , ( ~ t I III" !I : I Ii!: : I2. 0 ;1; ii.! I:i! rl I I I. . .. 'r "

~ ! ' l l . l fiT II II' ,'. i, tT1 111 III I] f 11

' i II,.II I,l "IIIJ 1,,'11'\l: :1' lji dl ' . . If Ililli ! 111 pi"''1::- ;m11 I I ; l ~ ! ! III fji Wi-. W I I r III til!1 tJlU. IW iii I I I . I f m ~ 1 , 1 [ ~ l i

40Ze o

,I, 0 ,40 ~ 12020 lb o

C U ~ f ! . 8 U T (fI1AJ C u ~ R E t - J - r ( r > 1 t 4 )TlST 9v


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Diode pumped results EDFA module cooled to "'10C to operate at "'971 nm. Approximately 500/0 of module light couples to fiber laser. Data are given in terms of applied current to the laser diode. Laser diode + fiber laser can form coupled laser cavities. LD monitor photodiode reads about 100/0 higher when coupled to fiber.

~ E 2.5---Ec 2~ ~to(tj 1.5L-a>

1a.......::J.8- 0.5::Jo

50

:IR = 58% II-

100 150laser diode current (rnA)


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Related resultsAssuming (1) 50% coupling efficiency,

(2) When coupled to fiber laser LD power increases by '" 10 %For an R = 58% @ 544 nm output coupler

threshold: "'21 mW (w.r.t.c.p.) slope efficiency: "'24% (w.r. t.c.p.) 2.5 mW of green light generated from "'31 mW of coupled 971 nm pump lightIn comparison:At BT Laboratories (Massicott, et al., Electron. Lett. 29, 2119 (1993)),a 1.1 J.lm core, 0.4 NA (Ac = 600 nm) Er fibre laser generated3 mW of green light from 40 mW of coupled 800 nm pump lightfrom an AIGaAs laser diode.


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"Warm-up" effectdiode pumped Er fiber warm up

1.--.. 0.5 .3:E--.. 0.2Q)

0.1a.+oJi1. 0.05S0c 0.02Q)~ 0.01

0 5 10 15 20 25 30minutes after turn-on

Highly dependent on pump power and fiber laser cavity loss Once warm, fiber stays warm for hours. "hand-waving" solution


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Summary Upconversion-pumped Er fiber lasers are capable of greater than 50% IR to

green efficiency. 2.5 mW of 544 nm light generated from a "40-mW" EDFA module. Results can be scaled to higher power: Doubling the diode pump power

should increase the green output to over 10 mW.

Compact Blue Green Lasers ppt.pdf

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