A compact and robust all-solid-state mid-infrared (MIR)laser pa 6.45 um ine high average simba rekubuda uye pedyo-Gaussian beam quality inoratidzwa.A maximum output power of 1.53 W ne pulse width inosvika 42 ns pa 10 kHz inowanikwa pachishandiswa ZnGeP2 (ZGP) Optical parametric oscillator (OPO)Avhareji yebeam quality factor inoyerwa kuita M2=1.19.
Uyezve, kusimba kwesimba kwepamusoro kunosimbiswa, nekuchinja kwesimba kusingasviki 1.35% rms pamusoro pe2 h, uye laser inogona kumhanya zvinobudirira kweanopfuura 500 h muhuwandu.Kushandisa iyi 6.45 um pulse senzvimbo yemwaranzi, kubviswa kwemhuka. Huropi hunoongororwa. Uyezve, chibvumirano chekukuvadza chinoongororwa kekutanga, kusvika pakuziva kwedu, uye mhedzisiro inoratidza kuti iyi MIR laser ine yakanakisa ablation kugona, ichiita iyo inogona kutsiva yemahara erekitironi lasers.©2022 Optica Publishing Group
https://doi.org/10.1364/OL.446336
Mid-infrared (MIR) 6.45 um laser radiation inogona kushandiswa munzvimbo dzemishonga yemhando yepamusoro nekuda kwekunaka kwayo kweyero yakakura yekubvisa uye kukuvadzwa kushoma kwechibvumirano 【1】.Mahara erekitironi lasers (FELs) ,strontium vapor lasers, gasi. Raman lasers, uye solid-state lasers yakavakirwa pane optical paramet-ric oscillator (OPO) kana musiyano frequency chizvarwa (DFG) anowanzo shandiswa 6.45 um laser masosi.Zvisinei, mutengo wakakwira, hukuru hukuru, uye chimiro chakaoma cheFELs chinodzikisira yavo. Strontium vapor lasers uye gasi Raman lasers inogona kuwana mabhendi anonangwa, asi ese ari maviri ane hurombo kugadzikana, pfupi ser-
Zvidzidzo zvakaratidza kuti 6.45 um solid-state lasers inoburitsa diki yekupisa dhamu-zera renji mumatishu ehupenyu uye kuti kudzika kwavo kwekubvisa kwakadzika kupfuura kweFEL pasi pemamiriro akafanana, ayo akasimbisa kuti anogona. Inoshandiswa seimwe nzira inoshanda kune FELs yebiological tissue ablation 【2】.Pamusoro pezvo,solid-state lasers ine zvakanakira compact structure,kugadzikana kwakanaka,uye
tabletop operation, zvichiita kuti vave maturusi anovimbisa ekuwana a6.45μn light source.Sezvinozivikanwa, nonlinear infrared crystals anoita basa rakakosha mu frequency conversion process inoshandiswa kuwana yakakwirira-performance MIR lasers.Kuenzaniswa neoxide infrared crys-tals ine 4 um cut-off edge, asiri-oxide makristasi ari mushe. inokodzera kugadzira MIR lasers. Makristasi aya anosanganisira mazhinji emachalcogenides, akadai seAgGaS2 (AGS) 【3,41, LiInS2 (LIS) 【5,61, LilnSe2 (LISe) 【7】 BGSGaS, 9 】, uye BaGaSe (BGSe) 【10-12】, pamwe chete nemakomisheni e phosphorus CdSiP2 (CSP) 【13-16】 uye ZnGeP2 (ZGP) 【17】; maviri ekupedzisira maviri asina kuwirirana akakura. semuenzaniso, MIR mwaranzi inogona kuwanikwa uchishandisa CSP-OPOs.Zvisinei, maCSP-OPO mazhinji anoshanda pane ultrashort (pico-uye femtosecond) nguva sikero uye anopombwa neanosvika 1 um mode-akakiyiwa lasers. SPOPO) masisitimu ane gadziriso yakaoma uye inodhura. Mavhareji emasimba adzo zvakare akadzikira pane 100 mW pakutenderedza 6.45 um【13-16】.Kuenzaniswa neCSP crystal, ZGP ine yakakwirira laser damage threchengetedza (60 MW/cm2), yakakwira yekupisa conductiv-ity (0.36 W/cm K) uye inofananidzwa isina mutsara coefficient (75pm/V) .Nekudaro, ZGP yakanakisa MIR isiri-linear optical crystal yehukuru-simba kana yakakwirira- kushandiswa kwesimba 【18-221.Semuenzaniso,a flat-flat mhango ZGP-OPO ine tuning range ye 3.8-12.4 um yakapombwa ne2.93 um laser yakaratidzwa.Kunyanya simba rimwe-pulse rechiedza chisina basa pa6.6 um 1.2 mJ 【201.Nekuda kweiyo yavelength ye6.45 um, maxi-mum single-pulse energy ye5.67 mJ pakudzokorora frequency ye100 Hz yakawanikwa uchishandisa mhete isina kuronga OPO cavity yakabva paZGP crystal.Nekudzokorora kwekudzokorora kwe100 Hz. frequency ye200Hz,avhareji simba rekubuda re0.95 W rakasvikwa 【221.Sekuziva kwedu,iri ndiro simba repamusoro rinobuda pa6.45 um.Zvidzidzo zvagara zviripo zvinoratidza kuti simba repamusoro-soro rinodiwa pakubvisa nyama 【23】.Naizvozvo, kugadzirwa kwesimba repamusoro-soro 6.45 um laser source kungave kwakakoshera zvikuru mukusimudzira mushonga webhayoloji.Mutsamba iyi, tinoshuma yakapfava, compact all-solid-state MIR 6.45 um laser ine yakakwira avhareji yekubuda simba uye yakavakirwa paZGP-OPO inopombwa nenanosecond (ns)-pulse 2.09 um
Laser.Iyo yakanyanya avhareji yekuburitsa simba re6.45 um laser inosvika 1.53 W ine pulse hupamhi hunosvika makumi mana nembiri padzokororo frequency ye10 kHz, uye ine yakanakisa beam mhando. inoferefetwa.Iri basa rinoratidza kuti laser inzira inoshanda yekubvisa chaiyo tissuc,sezvo ichiita selaser scalpel.Iyo yekuyedza setup yakadhirowewa muFig.1.ZGP-OPO inopomba neyakagadzirwa LD-pumped 2.09 um Ho:YAG laser iyo inopa 28 W yeavhareji simba pa10 kHz.ine pulse duration inosvika 102 ns（ FWHM) neavhareji yebeam quality factor M2 inosvika 1.7.MI neM2 magirazi maviri 45 ane coating inopenya zvakanyanya pa 2.09 um.Magirazi aya anogonesa kudzora kutungamira kwepombi.Malenzi maviri anotarisisa (f1 =100mm ,f2=100 mm) anoiswa pakudhumhanisa danda rine dhayamita ringaita 3.5 mm mukristaro yeZGP.An optical isolator (ISO) inoshandiswa kudzivirira danda repombi kudzoka kune 2.09 um pombi source.A half-wave plate (HWP) pa2.09 um inoshandiswa kudzora polarization yepombi light.M3 neM4 iOPO cavity magirazi, ine flat CaF2 inoshandiswa se substrate material.Chionioni chemberi M3 chinopesana nereflection coated (98%) chepombi. danda uye yakakwira-reflection yakavharwa ((98%) ye6.45 um idler uye 3.09 um signal waves. Iyo yekubuda-inoisa girazi M4 inoratidzira zvakanyanya (98%) pa2.09um uye 3.09 um uye inobvumira kutapurirana kwechikamu che6.45 um idler.Iyo ZGP crystal yakachekwa pa6-77.6 ° andp = 45 ° yemhando-JⅡ chikamu chinofananidzwa 【2090.0 (o) 6450.0 (o)+3091.9 (e)】, iyo inonyanya kukodzera kune chaiyo wavelength parameter uye wavelength wavelength. mutsara uchienzaniswa nerudzi-I chikamu chinofananidzwa. Zviyero zvekristaro yeZGP i5mm x 6 mm x 25 mm, uye yakakwenenzverwa uye inodzivirira kuratidzira yakavharwa kumativi ese ari maviri ekupedzisira kwemafungu matatu ari pamusoro. Yakaputirwa mu indium foil uye yakagadzikwa mudhishi yekupisa yemhangura ine kutonhora kwemvura (T=16)).Kureba kwegomba i27 mm.Nguva yekufamba-kudzoka yeOPO i0.537 ns yepombi laser.Takaedza chikumbaridzo chekukuvadzwa kwekristaro yeZGP neR. -on-I nzira 【17】.Chikumbaridzo chekukuvadza chekristaro cheZGP chakayerwa kuita 0.11 J/cm2 pa10 kHz.mukuedza,zvichienderana nepamusoro pesimba guru re1.4 MW/cm2,iyo yakadzikira nekuda kwe husina kunaka hwekupfeka.Simba rinobuda rechiedza chakagadzirwa chisina basa chinoyerwa nemamita esimba (D, OPHIR, 1 uW kusvika 3 W), uye kureba kwechiedza chechiratidzo kunotariswa ne spectrometer (APE, 1.5-6.3 m). kuwana simba repamusoro rekubuda kwe6.45 um, isu tinogadzirisa dhizaini yezviyero zveOPO. A manhamba simulation inoitwa zvichibva patatu-wave mixing theory uye paraxial propagation cquations 【24,25】; mune simulation, isu shandisa maparamendi anoenderana nemamiriro ekuedzwa uye tora kupuruzira kwekuisa neGaussian mbiri munzvimbo nenguva. Hukama huripo pakati peOPO inobuda girazi
transmittance, simba repombi kusimba, uye kubuda zvakanaka kunogadziriswa nekushandisa pombi danda density mugomba kuti riwane simba repamusoro rekubuda uku panguva imwe chete ichidzivirira kukuvadzwa kwekristaro yeZGP uye zvinhu zvemaziso. W yeZGP-OPO oparesheni.Simulated mhedzisiro inoratidza kuti nepo optimal inobuda coupler ine transmittance ye50% inoshandiswa, iyo yepamusoro peak simba density ingori 2.6 x 10 W/cm2 muZGP kuchema-tal, uye avhareji simba rekubuda. inopfuura 1.5 W inogona kuwanikwa.Mufananidzo 2 unoratidza hukama pakati peyero yakayerwa yakabuda simba reusimbe pa 6.45 um uye chiitiko chepombi simba.Inogona kuonekwa kubva Fig.2 kuti simba rinobuda reusimbe rinowedzera monotonously ne chiitiko chepombi simba.Chikumbaridzo chepombi chinoenderana neavhareji simba repombi re 3.55WA rinokwanisa kubuda simba risingashande re 1.53 W rinowanikwa pasimba repombi rinoita 18.7 W, rinoenderana nekuona-ku-optical kupinduka kwakanaka of ingangoita 8.20%% uye quantum conversion cfliciency ye25.31%.Nekuchengetedza kwenguva refu,laser inoshandiswa pedyo ne70% yesimba rayo guru rekubuda kunze.Kusimba kwesimba kunoyerwa pasimba rinobuda reIW, se inoratidzwa mune inset (a) muFig.2.Inowanikwa kuti kuyerwa kwesimba kushanduka kuri pasi pe1.35% rms mu2 h, uye kuti laser inogona kushanda zvakanaka kweanopfuura 500 h muhuwandu.Kureba kwechiratidzo chechiratidzo inoyerwa pachinzvimbo cheasina basa nekuda kwekuganhurwa kwewavelength ye spectrometer (APE, 1.5-6.3 um) inoshandiswa mukuedza kwedu.Chiyero chechiratidzo chewavelength chiri pakati pe 3.09 um uye upamhi hwemutsara hunosvika 0.3 nm, sezvaratidzwa in inset (b) yeFig.2.The central wavelength yeusimbe inobva yaonekwa kuti i 6.45um.Kupopudza kwehupamhi hweusimbe hunoonekwa nephotodetector (Thorlabs,PDAVJ10) uye yakanyorwa ne digital oscilloscope (Tcktronix), ）。Yakafanana oscilloscope waveform inoratidzwa muFig.3 uye inoratidza kupuruzira kwehupamhi hunosvika 42 ns. The pulse widthiri 41.18% yakamanikana kune 6.45 um idler kana ichienzaniswa ne2.09 um pump pulse nekuda kweiyo temporal kuwana kupfupika kweiyo nonlinear frequency conversion process.Nekuda kweizvozvo, inoenderana idler pulse peak simba i3.56kW. The beam quality factor ye 6.45 um idler inopimwa nelaser beam
analyzer (Spiricon, M2-200-PIII) pa 1 W yesimba rinobuda, sezvinoratidzwa muFig.4.Makoshero akayerwa eM2 neM, 2 ari 1.32 uye 1.06 pamwe chete ne x axis uye y axis, zvakateerana, zvinoenderana ne avhareji yemhando yemhando yeM2 = 1.19.Insct yeFig.4 inoratidza maviri-dimensional (2D) beam intensity profile, ine pedyo-Gaussian spatial mode.Kuona kuti 6.45 um pulse inopa inoshanda abla-tion, kuyedza-ye-principle kuedza kunosanganisira laser ablation yeporcine brain inoitwa.An f = 50 lens inoshandiswa kutarisa 6.45 um pulse beam kusvika muchiuno radius inenge 0.75 mm.Chinzvimbo chinofanira kubviswa pane porcine brain tissue inoiswa panzvimbo yakatarisa yelaser beam.Kupisa kwepamusoro (T) kwebiological tissue sekushanda kwenzvimbo yeradial r meas-ured ne thermocamera (FLIR A615) synchronously panguva yekubvisa. ,2,4,6,10,uye 20s palaser power yeI W.Panguva yega yega yekudiridza,masample positions matanhatu anoburitswa:r=0,0.62,0.703,1.91,3.05, uye 4.14 mm pamwe chete neradial direction maererano nechepakati penzvimbo yeradiation, sezvinoratidzwa mumufananidzo. paablation position panyama inowedzera nekuwedzera nguva yeradiation.Iyo yakanyanya tembiricha T panzvimbo yepakati r=0 i132.39,160.32,196.34;
205.57,206.95, uye 226.05C kwenguva yeradiation ye1,2,4,6,10, uye 20 s, zvakateerana.Kuongorora kukuvara kwechibvumirano, kugoverwa kwetembiricha pane yakabviswa tishu inofananidzwa. Izvi zvinoitwa zvinoenderana ne iyo thermal conduction theory yebiological tissue126】 uye dzidziso yekupararira kwelaser mune biological tishu [27】 yakasanganiswa neiyo optical paramita yeporcine brain 1281.
Kufananidza kunoitwa nekufungidzira kwekupinza Gaussian beam. Sezvo iyo biological tissue inoshandiswa muexper-iment iri yega porcine brain tissue, pesvedzero yeropa nemetabolism pane tembiricha inofuratirwa, uye porcine brain tissue inorerutswa kupinda chimiro chesilinda yesimula-tion.Matanho anoshandiswa mukufananidza anopfupikiswa muTebhura 1.Makavha akasimba anoratidzwa muFig.5 ndiwo anofananidzwa kugoverwa kwekushisa kweradial tembiricha maererano neablation centre pamatishu pamusoro pezvitanhatu zvakasiyana. durations.Vanoratidza Gaussian tembiricha profile kubva pakati kusvika periphery.Zviri pachena kubva Fig.5 kuti experimental data agrce zvakanaka pamwe simulated migumisiro.Izvo zvakare pachena kubva Fig.5 kuti simulated tembiricha iri pakati penzvimbo. ablation position inowedzera sezvo nguva ye irradia-tion ichiwedzera paradiation yega yega. Tsvakurudzo yapfuura yakaratidza kuti masero ari munyama akachengeteka zvakakwana pamhepo pazasi.55C, zvinoreva kuti masero anoramba achishanda munzvimbo dzakasvibirira (T <55C) dzema curves muFig.5. The yellow zone of each curve (55C)60C）。Inogona kucherechedzwa muFig.5 kuti iyo simulated ablation radii paT = 60 ° Care0.774,0.873,0.993,1.071,1.198 uye 1.364 mm, zvichiteerana, kwenguva yeradiation ye1,2,4,6, 10, uye 20s, ukuwo akafananidzirwa ablation radii paT=55C ari0.805,0.908,1.037,1.134,1.271, uye1.456 mm, zvakateerana. 2.394,3.098,3.604,4.509,uye 5.845 mm2 ye1,2,4,6,10,uye 20s yeradiation, zvakateerana.Nzvimbo ine collateral damage area inowanikwa iine 0.003,0.0040.006,0.013,0.017,0.017,0. uye 0.027 mm2. Zvinogona kuonekwa kuti laser ablation zones uye nzvimbo dzekukuvadzwa kwechibvumirano dzinowedzera nenguva yeirradiation.Tinotsanangura chiyero chekukuvadza kwechibvumirano kuti ive chiyero chenzvimbo yekukuvara kwechibvumirano pa 55C s T60C. The collateral damage ratio inowanikwa. kusvika pa8.17%,8.18%,9.06%,12.11%,12.56%, uye 13.94% yenguva dzakasiyana dzeradiation,zvinoreva kuti kukuvadzwa kwechibatiso chenyama dzakabviswa idiki.Naizvozvo, kuyedza kwakadzamal data nemhedzisiro yekuenzanisa inoratidza kuti iyi compact, yakakwirira-simba,-yose-yakasimba-nyika 6.45 um ZGP-OPO laser inopa inobudirira ablation yebiological tissues.Pakupedzisira, takaratidza compact,high-simba,-yose-yakasimba-nyika. MIR pulsed 6.45 um laser source yakavakirwa panzira ye ns ZGP-OPO. Simba guru repakati pe 1.53 W rakawanikwa nepamusoro pesimba re3.65kW uye avhareji yemhando yemhando yeM2 = 1.19.Kushandisa iyi 6.45 um MIR mwaranzi, a proof-of-principle experiment on the laser ablation of tissue yakaitwa.Kuparadzirwa kwetembiricha pane ablated tissue surface kwakayerwa zviyedzwa uye ne theoretically simu-lated.Data yakayerwa yakabvumirana zvakanaka nezvakange zvaitwa.Zvakare, kukuvadzwa kwechibatiso kwakaongororwa. kekutanga. Izvi zvabuda zvinoratidza kuti tabletop yedu MIR pulse laser pa6.45 um inopa kubviswa kunobudirira kwebiological tissucs uye ine mukana mukuru wekuva chishandiso chinoshanda mukurapa nesayenzi yebhayoloji, sezvo inogona kutsiva yakakura FEL se.laser scalpel.