Ho:YAG - Njira Yabwino Yopangira 2.1-μm Laser Emission
Mafotokozedwe Akatundu
Laser thermokeratoplasty (LTK) yakula kwambiri m'zaka zaposachedwa. Mfundo yaikulu ndikugwiritsa ntchito mphamvu ya photothermal ya laser kuti ulusi wa collagen kuzungulira cornea uchepetse ndi kupindika kwapakati kwa cornea kukhala kurtosis, kuti akwaniritse cholinga chokonza hyperopia ndi hyperopic astigmatism. Holmium laser (Ho: YAG laser) imatengedwa kuti ndi chida choyenera cha LTK. Kutalika kwa laser Ho:YAG ndi 2.06μm, yomwe ndi yapakati pa infrared laser. Ikhoza kuyamwa bwino ndi minofu ya cornea, ndipo chinyezi cha cornea chikhoza kutenthedwa ndipo ulusi wa collagen ukhoza kuchepetsedwa. Pambuyo pa photocoagulation, kukula kwa corneal surface coagulation zone ndi pafupifupi 700μm, ndipo kuya kwake ndi 450μm, komwe kuli mtunda wotetezeka kuchokera ku corneal endothelium. Popeza Seiler et al. (1990) adagwiritsa ntchito koyamba Ho:YAG laser ndi LTK m'maphunziro azachipatala, Thompson, Durrie, Alio, Koch, Gezer ndi ena motsatizana anafotokoza zotsatira za kafukufuku wawo. Ho: YAG laser LTK yakhala ikugwiritsidwa ntchito kuchipatala. Njira zofananira zowongolera hyperopia zimaphatikizapo radial keratoplasty ndi excimer laser PRK. Poyerekeza ndi radial keratoplasty, Ho:YAG ikuwoneka kuti ikuwonetseratu za LTK ndipo sichifuna kuyika kafukufuku mu cornea ndipo sichimayambitsa corneal tissue necrosis m'dera la thermocoagulation. Excimer laser hyperopic PRK imangosiya mtundu wapakati wa 2-3mm popanda kutulutsa, zomwe zitha kuchititsa khungu komanso kunyezimira usiku kuposa Ho: YAG LTK imasiya pakati pa 5-6mm. makhiristo awonetsa ma 14 inter-multifold laser channels, omwe akugwira ntchito mongoyembekezera kuchokera ku CW kupita ku mode-lock. Ho:YAG imagwiritsidwa ntchito ngati njira yabwino yopangira 2.1-μm laser emission kuchokera pakusintha kwa 5I7- 5I8, pakugwiritsa ntchito monga laser remote sensing, opaleshoni yachipatala, ndi kupopera Mid-IR OPO's kuti akwaniritse 3-5micron emission. Direct diode pumped systems ndi Tm: Fiber Laser pumped systems[4] zasonyeza mayendedwe otsetsereka, ena akuyandikira malire ongoyerekeza.
Basic Properties
| Ho3+ concentration range | 0.005 - 100 atomiki% |
| Emission Wavelength | 2.01 ku |
| Kusintha kwa Laser | 5I7 → 5I8 |
| Flouresence Moyo wonse | 8.5 mz |
| Pampu Wavelength | 1.9m uwu |
| Coefficient of Thermal Expansion | 6.14 x 10-6 K-1 |
| Thermal Diffusivity | 0.041 cm2 s-2 |
| Thermal Conductivity | 11.2 W m-1 K-1 |
| Kutentha Kwapadera (Cp) | 0,59 J g-1 K-1 |
| Thermal Shock Resistant | 800 W m-1 |
| Refractive Index @ 632.8 nm | 1.83 |
| dn/dT (Thermal Coefficient of Refractive Index) @ 1064nm | 7.8 10-6 K-1 |
| Kulemera kwa Maselo | 593.7 g ufa - 1 |
| Melting Point | 1965 ℃ |
| Kuchulukana | 4.56 g cm-3 |
| Kulimba kwa MOHS | 8.25 |
| Young's Modulus | 335 g pa |
| Kulimba kwamakokedwe | 2 gpa |
| Kapangidwe ka Crystal | Kiyubiki |
| Standard Orientation | |
| Y3+ Site Symmetry | D2 |
| Lattice Constant | ndi = 12.013 Å |
