479:
defect, thereby improving system efficiency, reducing cooling requirements, and enabling further TEM00 power scaling. Because of the narrow 885-nm absorption feature in Nd:YAG, certain systems may benefit from the use of wavelength-locked diode pump sources, which serve to narrow and stabilize the pump emission spectrum to keep it closely aligned to this absorption feature. To date, high power diode laser locking schemes such as internal distributed feedback Bragg gratings and externally aligned volume holographic grating optics, VHG’s, have not been widely implemented due to the increased cost and assumed performance penalty of the technology. However, recent advancements in the manufacture of stabilized diode pump sources which utilize external wavelength locking now offer improved spectral properties with little-to-no impact on power and efficiency. Benefits of this approach include improvements in laser efficiency, spectral linewidth, and pumping efficiency.
400:
94:
737:
284:
478:
Neodymium-doped solid state lasers continue to be the laser source of choice for industrial applications. Direct pumping of the upper Nd laser level at 885-nm (rather than at the more traditional broad 808-nm band) offers the potential of improved performance through a reduction in the lasing quantum
352:
In the realm of very high output powers, the KTP crystal becomes susceptible to optical damage. Thus, high-power DPSSLs generally have a larger beam diameter, as the 1064 nm laser is expanded before it reaches the KTP crystal, reducing the irradiance from the infrared light. In order to maintain
259:
The end face of the diode along the fast axis can be imaged onto strip of 1 μm height. But the end face along the slow axis can be imaged onto a smaller area than 100 μm. This is due to the small divergence (hence the name: 'slow axis') which is given by the ratio of depth to width. Using
263:
So to get a beam which is equal divergence in both axis, the end faces of a bar composed of 5 laser diodes, can be imaged by means of 4 (acylindrical) cylinder lenses onto an image plane with 5 spots each with a size of 5 mm x 1 mm. This large size is needed for low divergence beams. Low
471:
On the other hand, diode lasers are cheaper and more energy efficient. As DPSSL crystals are not 100% efficient, some power is lost when the frequency is converted. DPSSLs are also more sensitive to temperature and can only operate optimally within a small range. Otherwise, the laser would suffer
463:
DPSSLs generally have a higher beam quality and can reach very high powers while maintaining a relatively good beam quality. Because the crystal pumped by the diode acts as its own laser, the quality of the output beam is independent of that of the input beam. In comparison, diode lasers can only
382:
DPSSLs use an even more complicated process: An 808 nm pump diode is used to generate 1,064 nm and 1,342 nm light, which are summed in parallel to become 593.5 nm. Due to their complexity, most yellow DPSSLs are only around 1% efficient, and usually more expensive per unit of
287:
Neodymium ions in various types of ionic crystals, and also in glasses, act as a laser gain medium, typically emitting 1,064 nm light from a particular atomic transition in the neodymium ion, after being "pumped" into excitation from an external source. Selection of 946 nm transition light is
363:
DPSSLs use a nearly identical process, except that the 808 nm light is being converted by an Nd:YAG crystal to 946 nm light (selecting this non-principal spectral line of neodymium in the same Nd-doped crystals), which is then frequency-doubled to 473 nm by a
464:
reach a few hundred milliwatts unless they operate in multiple transverse mode. Such multi-mode lasers have a larger beam diameter and a greater divergence, which often makes them less desirable. In fact, single-mode operation is essential in some applications, such as
341:
crystal, producing 532 nm light. Green DPSSLs are usually around 20% efficient, although some lasers can reach up to 35% efficiency. In other words, a green DPSSL using a 2.5 W pump diode would be expected to output around 500-900 mW of 532 nm light.
267:
Also in the paraxial case it is much easier to use gold or copper mirrors or glass prisms to stack the spots on top of each other, and get a 5 x 5 mm beam profile. A second pair of (spherical) lenses image this square beam profile inside the laser crystal.
205:, which is placed precisely over the diode (but behind the micro-lens). At the other end of the fiber bundle, the fibers are fused together to form a uniform, gap-less, round profile on the crystal. This also permits the use of a remote power supply.
169:
High power lasers use a single crystal, but many laser diodes are arranged in strips (multiple diodes next to each other in one substrate) or stacks (stacks of substrates). This diode grid can be imaged onto the crystal by means of a
174:. Higher brightness (leading to better beam profile and longer diode lifetimes) is achieved by optically removing the dark areas between the diodes, which are needed for cooling and delivering the current. This is done in two steps:
264:
divergence allows paraxial optics, which is cheaper, and which is used to not only generate a spot, but a long beam waist inside the laser crystal (length = 50 mm), which is to be pumped through its end faces.
386:
Another method is to generate 1,064 and 1,319 nm light, which are summed to 589 nm. This process is more efficient, with about 3% of the pump diode's power being converted to yellow light.
368:(BBO) crystal or LBO crystal. Because of the lower gain for the materials, blue lasers are relatively weak, and are only around 3-5% efficient. In the late 2000s, it was discovered that
376:, which degrades the crystal if it is exposed to moisture. In continuous-wave laser applications, however, BiBO may exhibit instabilities which degrade its performance.
349:
has a conversion efficiency of 60%, while KTP has a conversion efficiency of 80%. In other words, a green DPSSL can theoretically have an overall efficiency of 48%.
1004:
671:
369:
154:
The wavelength of laser diodes is tuned by means of temperature to produce an optimal compromise between the absorption coefficient in the crystal and
589:
372:(BiBO) crystals were more efficient than BBO or LBO for second harmonic generation in mode-locked lasers and do not have the disadvantage of being
472:
from stability issues, such as hopping between modes and large fluctuations in the output power. DPSSLs also require a more complex construction.
421:
115:
460:
DPSSLs and diode lasers are two of the most common types of solid-state lasers. However, both types have their advantages and disadvantages.
726:
885:
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903:
318:
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141:
590:"589 nm light generation by intracavity mixing in a Nd:YAG laser | Browse Journal - Journal of Applied Physics"
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123:
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425:
119:
624:
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163:
623:
Fu, R. J.; Hwang, C. J.; Wang, C. S. (16 July 1986). Feinberg, Rick; Holmes, Lewis; Levitt, Morris (eds.).
256:
and depending on the cooling technique for the whole bar (100 to 200) μm distance to the next laser diode.
213:
High power laser diodes are fabricated as bars with multiple single strip laser diodes next to each other.
68:
DPSSLs have advantages in compactness and efficiency over other types, and high power DPSSLs have replaced
1095:
338:
155:
593:
712:
271:
A volume of 0.001 mm active volume in the laser diode is able to saturate 1250 mm in a Nd:YVO
805:
879:
760:
410:
314:
104:
1069:
551:
414:
108:
862:
73:
893:
873:
325:) crystal which produces 1064 nm wavelength light from the main spectral transition of
636:
563:
17:
190:
8:
856:
76:
in many scientific applications, and are now appearing commonly in green and other color
640:
567:
652:
365:
1044:
194:
868:
740:
656:
354:
39:
644:
571:
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Diode lasers can also be precisely modulated with a greater frequency than DPSSLs.
334:
201:
The beams from multiple diodes can also be combined by coupling each diode into an
575:
159:
532:
972:
826:
496:
1084:
1054:
1014:
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514:
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77:
43:
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the above numbers the fast axis could be imaged onto a 5 μm wide spot.
1064:
1059:
1009:
821:
773:
768:
629:
Society of Photo-Optical
Instrumentation Engineers (Spie) Conference Series
55:
704:
1029:
1024:
1019:
967:
752:
353:
a lower beam diameter, a crystal with a higher damage threshold, such as
179:
62:
47:
158:(lowest possible pump photon energy). As waste energy is limited by the
977:
851:
843:
631:. Scientific and Engineering Applications of Commercial Laser Devices.
373:
293:
648:
326:
303:
69:
613:
Yellow lasers with 2.5 W pump diodes have reached up to around 80 mW
399:
93:
1049:
982:
307:
918:
58:
310:
1034:
736:
186:
625:"Single Mode Diode Laser For Optical Scanning And Recording"
189:
at reduced size into the crystal. The crystal can be pumped
216:
Each single strip diode typically has an active volume of:
51:
178:
The "fast axis" is collimated with an aligned grating of
1005:
ZEUS-HLONS (HMMWV Laser
Ordnance Neutralization System)
283:
552:"Generation of UV light by frequency doubling in BIBO"
1082:
672:"Commercial High-Efficiency 885-nm Diode Lasers"
292:The most common DPSSL in use is the 532 nm
162:this means higher power densities compared to
720:
389:
734:
622:
550:Ruseva, Valentina; Hald, Jan (2004-06-01).
428:. Unsourced material may be challenged and
122:. Unsourced material may be challenged and
727:
713:
549:
448:Learn how and when to remove this message
278:
142:Learn how and when to remove this message
886:Neodymium-doped yttrium lithium fluoride
282:
185:The partially collimated beams are then
14:
1083:
904:Neodymium-doped yttrium orthovanadate
708:
319:neodymium-doped yttrium orthovanadate
582:
525:
426:adding citations to reliable sources
393:
313:laser diode pumps a neodymium-doped
120:adding citations to reliable sources
87:
669:
24:
25:
1107:
915:Yttrium calcium oxoborate (YCOB)
693:
735:
398:
92:
1040:Laboratory for Laser Energetics
208:
962:Diode-pumped solid-state laser
663:
616:
607:
543:
507:
489:
164:high-intensity discharge lamps
32:diode-pumped solid-state laser
13:
1:
533:"BIBO Crystal for Blue Laser"
482:
345:In optimal conditions, Nd:YVO
576:10.1016/j.optcom.2004.03.033
7:
83:
10:
1112:
390:Comparison to diode lasers
992:
954:
841:
814:
759:
747:
306:) 808 nm wavelength
197:from three or more sides.
880:Yttrium lithium fluoride
761:Yttrium aluminium garnet
357:(LBO), is used instead.
329:ion. This light is then
315:yttrium aluminium garnet
1070:List of petawatt lasers
193:from both end faces or
74:flashlamp-pumped lasers
863:Terbium gallium garnet
519:www.unitedcrystals.com
501:www.unitedcrystals.com
302:. A powerful (>200
289:
279:Common DPSSL processes
894:Yttrium orthovanadate
874:Solid-state dye laser
556:Optics Communications
286:
1091:Semiconductor lasers
537:www.redoptronics.com
497:"Nd:YVO4 Properties"
422:improve this section
116:improve this section
857:Yttrium iron garnet
753:Semiconductor laser
641:1986SPIE..610..138F
568:2004OptCo.236..219R
56:neodymium-doped YAG
1096:Solid-state lasers
741:Solid-state lasers
366:beta barium borate
290:
1078:
1077:
876:(SSDL/SSOL/SSDPL)
869:Ti:sapphire laser
748:Distinct subtypes
649:10.1117/12.956398
635:. SPIE: 138–141.
458:
457:
450:
370:bismuth triborate
355:lithium triborate
335:nonlinear optical
331:frequency doubled
288:possible, as well
254:
253:
156:energy efficiency
152:
151:
144:
50:, for example, a
40:solid-state laser
16:(Redirected from
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592:. Archived from
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562:(1–3): 219–223.
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515:"KTP Properties"
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1045:Laser Mégajoule
993:Specific lasers
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700:Sam's laser FAQ
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670:Leisher, Paul.
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973:Figure-8 laser
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466:optical drives
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1055:Mercury laser
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1038:
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1016:
1015:Cyclops laser
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1000:Trident laser
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596:on 2011-07-22
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407:This section
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337:process in a
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101:This section
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49:
45:
41:
37:
33:
27:Type of laser
19:
1065:Vulcan laser
1010:Nova (laser)
961:
774:Er:YAG laser
769:Nd:YAG laser
679:. Retrieved
665:
632:
628:
618:
609:
598:. Retrieved
594:the original
584:
559:
555:
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438:January 2023
435:
420:Please help
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385:
379:
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360:
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351:
344:
330:
296:
291:
270:
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247:optical axis
228:100 μm
215:
212:
209:Some numbers
200:
195:transversely
168:
160:thermal lens
153:
138:
132:January 2023
129:
114:Please help
102:
67:
35:
31:
29:
1030:Shiva laser
1025:Argus laser
1020:Janus laser
968:Fiber laser
831:Er:Yb:glass
374:hygroscopic
180:cylindrical
63:laser diode
48:gain medium
1085:Categories
978:Disk laser
955:Structures
852:Ruby laser
844:gain media
600:2010-11-17
483:References
294:wavelength
250:slow axis
70:ion lasers
802:Ce:Gd:YAG
784:Nd:Ce:YAG
778:Nd:Cr:YAG
657:137632453
409:does not
327:neodymium
275:crystal.
244:fast axis
225:2 mm
222:1 μm
103:does not
61:, with a
1050:LULI2000
983:F-center
929:Ce:LiCAF
926:Ce:LiSAF
888:(Nd:YLF)
834:Yb:glass
827:Er:glass
822:Nd:glass
677:. nLIGHT
333:using a
308:infrared
84:Coupling
46:a solid
42:made by
1060:ISKRA-6
964:(DPSSL)
947:Yb:SFAP
932:Cr:ZnSe
919:Nd:YCOB
906:(Nd:YVO
637:Bibcode
564:Bibcode
430:removed
415:sources
383:power.
321:(Nd:YVO
124:removed
109:sources
59:crystal
44:pumping
38:) is a
941:Sm:CaF
882:(YLF)
842:Other
806:Gd:YAG
799:Ce:YAG
796:Tb:YAG
793:Sm:YAG
790:Dy:YAG
787:Ho:YAG
781:Yb:YAG
681:18 May
655:
380:Yellow
311:GaAlAs
239:Width
233:Height
187:imaged
1035:HiPER
985:laser
935:U:CaF
921:laser
865:(TGG)
859:(YIG)
815:Glass
675:(PDF)
653:S2CID
297:green
236:Depth
54:or a
36:DPSSL
896:(YVO
683:2012
633:0610
413:any
411:cite
361:Blue
172:lens
107:any
105:cite
72:and
52:ruby
18:DPSS
645:doi
572:doi
560:236
424:by
339:KTP
118:by
1087::
900:)
651:.
643:.
627:.
570:.
558:.
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535:.
517:.
499:.
468:.
304:mW
166:.
80:.
65:.
30:A
943:2
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898:4
728:e
721:t
714:v
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436:(
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323:4
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139:(
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130:(
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34:(
20:)
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