©2001 CRC Press LLC Ce 3 + Ti 3 + Cr 3+ Cr 4 + Sm + 2 V + 2 Wavelength ( µm) 0.5 1.0 1.5 2.0 4 (SrF ) 2 (MgF ) 2 (LiYF ) 4 6 (BeAl O , LiSrAlF ) 2 (Mg SiO ) 2 Co + 2 (MgF ) 2 (Al O ) 3 2 Ni + 2 (MgF , MgO) 2 2.5 Figure 1.1.11 Reported wavelength ranges of representative tunable crystalline lasers operating at room temperature (from the Handbook of Laser Wavelengths, CRC Press, Boca Raton, FL, 1998). Upconversion processes make possible many additional lasing transitions and excitation schemes. Upconversion excitation techniques include multi-step absorption, ion-ion energy transfer, excited state absorption, and photon avalanche processes. Lasers based on upconversion schemes are noted in the mode column of the laser tables. Transitions involved in upconversion processes are given in Table 1.1.3 and can be identified by reference to the relevant energy level diagrams for the ions in Figures 1.1.4–1.1.8. The success of many of the schemes depends upon the degree of resonance of energy transfer transitions and the rate of nonradiative transitions by multiphonon emission and thus varies with the host crystal. Cascade and cross-cascade lasing schemes have also been employed; transitions involved in cascade and cross-cascade lasing schemes are summarized in Tables 1.1.4 and 1.1.5. For examples of avalanche-pumped upconversion lasers, see References 18 and 1037. ©2001 CRC Press LLC Table 1.1.3 Multi-step Upconversion Excitation Schemes optical transition ⇒ ion-ion energy transfer transitions ➟ nonradiative transition Laser ion Upper laser level Codopant ion Upconversion excitation scheme Pr 3+ 3 P 0 — Yb 3+ 1) 3 H 4 → 1 G 4 2) 1 G 4 → 3 P 1 ➟ 3 P 0 1) 2 F 7/2 → 2 F 5/2 (Yb 3+ ) 2) 2 F 5/2 – 2 F 7/2 (Yb 3+ ) ⇒ 3 H 4 – 1 G 4 (Pr 3+ ) 3) 1 G 4 → 3 P 1,0 Nd 3+ 4 D 3/2 — 1) 4 I 9/2 → 4 F 5/2 ➟ 4 F 3/2 2) 4 F 3/2 → 4 D 3/2 1) 4 I 9/2 → 4 G 5/2 ➟ 4 F 3/2 2) 4 F 3/2 → 4 D 3/2 2 P 3/2 — 1) 4 I 9/2 → 4 G 5/2 ➟ 4 F 3/2 2) 4 F 3/2 → 4 D 3/2 ➟ 2 P 3/2 Ho 3+ 5 S 2 Yb 3+ 1) 2 F 7/2 → 2 F 5/2 (Yb 3+ ) 2) 2 F 5/2 – 2 F 7/2 (Yb 3+ ) ⇒ 5 I 8 – 5 I 6 (Ho 3+ ) 3) 2 F 7/2 → 2 F 5/2 (Yb 3+ ) 4) 2 F 5/2 – 2 F 7/2 (Yb 3+ ) ⇒ 5 I 6 – 5 S 2 (Ho 3+ ) 5 I 7 Yb 3+ 1) 2 F 7/2 → 2 F 5/2 (Yb 3+ ) 2) 2 F 5/2 – 2 F 7/2 (Yb 3+ ) ⇒ 5 I 8 – 5 I 6 (Ho 3+ ) ➟ 5 I 7 Er 3+ 2 P 3/2 — 1) 4 I 15/2 → 4 I 11/2 (Er 1 3+ ) 2) 4 I 15/2 → 4 I 11/2 (Er 2 3+ ) 3) 4 I 11/2 – 4 I 15/2 (Er 1 3+ ) ⇒ 4 I 11/2 – 4 F 7/2 ➟ 4 S 3/2 (Er 2 3+ ) 4) 4 S 3/2 – 4 I 15/2 (Er 2 3+ ) ⇒ 4 F 9/2 – 2 K 13/2 (Er 3 3+ ) ➟ 2 P 3/2 4 G 11/2 — 1) 4 I 15/2 → 4 I 13/2 (fourfold) ⇒ 4 G 11/2 2 H 9/2 — 1) 4 I 15/2 → 4 I 11/2 (Er 1 3+ ) 2) 4 I 15/2 → 4 I 11/2 (Er 2 3+ ) 3) 4 I 11/2 – 4 I 15/2 (Er 1 3+ ) ⇒ 4 I 11/2 – 4 F 7/2 (Er 2 3+ ) ➟ 4 S 3/2 4) 4 I 15/2 → 4 I 11/2➟ 4 I 13/2 (Er 3 3+ ) 5) 4 S 3/2 – 4 I 15/2 (Er 2 3+ ) ⇒ 4 I 13/2 – 2 H 9/2 (Er 3 3+ ) ©2001 CRC Press LLC Table 1.1.3—continued Multi-step Upconversion Excitation Schemes Laser ion Upper laser level Codopant ion Upconversion excitation scheme 4 S 3/2 — — 1) 4 I 15/2 → 4 I 9/2 ➟ 4 I 11/2 2) 4 I 11/2 → 4 F 5/2,7/2 → ➟ 4 S 3/2 1) 4 I 15/2 → 4 I 11/2 (Er 1 3+ ) 2) 4 I 15/2 → 4 I 11/2 (Er 2 3+ ) 3) 4 I 11/2 – 4 I 15/2 (Er 1 3+ ) ⇒ 4 I 11/2 – 4 F 7/2 ➟ 4 S 3/2 (Er 2 3+ ) 4 F 9/2 Yb 3+ Yb 3+ 1) 2 F 7/2 → 2 F 5/2 (Yb 3+ ) 2) 4 I 15/2 → 4 I 13/2 (Er 3+ ) 3) 2 F 5/2 – 2 F 7/2 (Yb 3+ ) ⇒ 4 I 13/2 – 4 F 9/2 (Er 3+ ) 1) 2 F 7/2 → 2 F 5/2 (Yb 3+ ) 2) 2 F 5/2 – 2 F 7/2 (Yb 3+ ) ⇒ 4 I 15/2 – 4 I 11/2 (Er 3+ ) 3) 2 F 7/2 → 2 F 5/2 (Yb 3+ ) 4) 2 F 5/2 – 2 F 7/2 (Yb 3+ ) ⇒ 4 I 11/2 – 4 F 7/2 (Er 3+ ) ➟ 4 F 9/2 4 I 11/2 — 1) 4 I 15/2 → 4 I 13/2 (Er 1 3+ ) 2) 4 I 15/2 → 4 I 13/2 (Er 2 3+ ) 3) 4 I 13/2 – 4 I 15/2 (Er 1 3+ ) ⇒ 4 I 13/2 – 4 I 9/2 ➟ 4 I 11/2 (Er 2 3+ ) Tm 3+ 1 I 6 Yb 3+ 1) 2 F 7/2 → 2 F 5/2 (Yb 3+ ) 2) 2 F 7/2 – 2 F 5/2 (Yb 3+ ) ⇒ 3 H 6 – 3 H 5 (Tm 1 3+ ) ➟ 3 F 4 3) 2 F 7/2 → 2 F 5/2 (Yb 3+ ) 4) 2 F 5/2 2 F 7/2 (Yb 3+ ) ⇒ 3 F 4 3 F 3 (Tm 1 3+ ) ➟ 3 H 4 5) 3 F 3 – 3 H 6 (Tm 1 3+ ) ⇒ 3 F 3 – 1 D 2 (Tm 2 3+ ) 6) 2 F 7/2 → 2 F 5/2 (Yb 3+ ) 7) 2 F 5/2 2 F 7/2 (Yb 3+ ) ⇒ 1 D 2 3 P J (Tm 2 3+ ) ➟ 1 I 6 Tm 3+ 1 D 2 — 1) 3 H 6 → 3 H 4 2) 3 H 4 → 1 D 2 1) 3 H 6 → 3 H 4 (Tm 1 3+ ) 2) 3 H 6 → 3 H 4 (Tm 2 3+ ) 3) 3 H 4 – 3 H 6 (Tm 1 3+ ) ⇒ 3 H 4 – 1 D 2 (Tm 2 3+ ) Tm 3+ 3 H 4 Yb 3+ 1) 2 F 7/2 → 2 F 5/2 (Yb 3+ ) 2) 3 H 6 → 3 H 5 ➟ 3 F 4 (Tm 3+ ) 3) 2 F 5/2 – 2 F 7/2 (Yb 3+ ) ⇒ 3 F 4 – 3 F 2 (Tm 3+ ) ➟ 3 H 4 ©2001 CRC Press LLC Table 1.1.3—continued Multi-step Upconversion Excitation Schemes Laser ion Upper laser level Codopant ion Upconversion excitation scheme Tm 3+ 1 G 4 Yb 3+ 1) 2 F 7/2 → 2 F 5/2 (Yb 3+ ) 2) 2 F 7/2 – 2 F 5/2 (Yb 3+ ) ⇒ 3 H 6 – 3 H 5 (Tm 3+ ) ➟ 3 F 4 3) 2 F 7/2 → 2 F 5/2 (Yb 3+ ) 4) 2 F 5/2 2 F 7/2 (Yb 3+ ) ⇒ 3 F 4 3 F 2➟ 3 H 4 (Tm 3+ ) 5) 2 F 7/2 → 2 F 5/2 (Yb 3+ ) 6) 2 F 5/2 – 2 F 7/2 (Yb 3+ ) ⇒ 3 H 4 – 1 G 4 (Tm 3+ ) Table 1.1.4 Cascade Laser Schemes → lasing transition ➟ nonradiative transition Laser ion Cascade transitions Pr 3+ 3 P 0 → 1 G 4 → 3 F 4 3 P 0 → 1 G 4 → 3 H 5 Nd 3+ 4 F 3/2 → 4 I 13/2 → 4 I 11/2 Ho 3+ 5 S 2 → 5 I 5 → 5 I 6 5 S 2 → 5 I 5 → 5 I 7 5 S 2 → 5 I 6 → 5 I 8 5 S 2 → 5 I 7 → 5 I 8 5 S 2 → 5 I 5 ➟ 5 I 6 → 5 I 7 5 S 2 → 5 I 5 ➟ 5 I 6 → 5 I 8 5 S 2 → 5 I 5 ➟ 5 I 6 → 5 I 7 → 5 I 8 5 S 2 → 5 F 5 ➟ 5 I 4 ➟ 5 I 5 → 5 I 6 → 5 I 7 5 I 6 → 5 I 7 → 5 I 8 Er 3+ 4 S 3/2 → 4 I 9/2 → 4 I 11/2 4 S 3/2 → 4 I 9/2 → 4 I 13/2 4 S 3/2 → 4 I 11/2 → 4 I 13/2 4 S 3/2 → 4 I 13/2 → 4 I 15/2 4 S 3/2 → 4 I 9/2 ➟ 4 I 11/2 → 4 I 13/2 4 S 3/2 → 4 I 9/2 ➟ 4 I 11/2 → 4 I 13/2 → 4 I 15/2 4 F 9/2 → 4 I 11/2 → 4 I 13/2 4 I 11/2 → 4 I 13/2 → 4 I 15/2 Tm 3+ 3 F 4 → 3 H 5 ➟ 3 H 4 → 3 H 6 ©2001 CRC Press LLC Table 1.1.5 Cross-Cascade Laser Schemes → lasing transition ⇒ nonradiative energy transfer transitions Laser ions Cross-cascade transitions Er 3+ + Ho 3+ 4 S 3/2 → 4 I 13/2 (Er 3+ ) 4 I 13/2 – 4 I 15/2 (Er 3+ ) ⇒ 5 I 8 – 5 I 7 (Ho 3+ ) 5 I 7 → 5 I 8 (Ho 3+ ) 4 I 11/2 → 4 I 13/2 (Er 3+ ) 4 I 13/2 – 4 I 15/2 (Er 3+ ) ⇒ 5 I 8 – 5 I 7 (Ho 3+ ) 5 I 7 → 5 I 8 (Ho 3+ ) Er 3+ + Tm 3+ 4 S 3/2 → 4 I 13/2 (Er 3+ ) ⇒ 4 I 13/2 – 4 I 15/2 (Er 3+ ) ⇒ 3 H 6 – 3 F 4 (Tm 3+ ) 3 F 4 → 3 H 6 (Tm 3+ ) 4 I 11/2 → 4 I 13/2 (Er 3+ ) 4 I 13/2 – 4 I 15/2 (Er 3+ ) ⇒ 3 H 6 – 3 F 4 (Tm 3+ ) 3 F 4 → 3 H 6 (Tm 3+ ) Tm 3+ + Ho 3+ 3 H 4 → 3 H 5 ➟ 3 F 4 (Tm 3+ ) 3 F 4 – 3 H 6 (Tm 3+ ) ⇒ 5 I 8 – 5 I 7 (Ho 3+ ) 55 I 7 → 5 I 8 (Ho 3+ ) 3 H 4 → 3 F 4 (Tm 3+ ) 3 F 4 – 3 H 6 (Tm 3+ ) ⇒ 5 I 8 – 5 I 7 (Ho 3+ ) 55 I 7 → 5 I 8 (Ho 3+ ) Er 3+ + Tm 3+ + Ho 3+ 4 I 11/2 → 4 I 13/2 (Er 3+ ) 4 I 13/2 – 4 I 15/2 (Er 3+ ) ⇒ 3 H 6 – 3 F 4 (Tm 3+ ) 3 F 4 – 3 H 6 (Tm 3+ ) ⇒ 5 I 8 – 5 I 7 (Ho 3+ ) 55 I 7 → 5 I 8 (Ho 3+ ) ©2001 CRC Press LLC Further Reading Caird, J. and Payne, S. A., Crystalline Paramagnetic Ion Lasers, in Handbook of Laser Science and Technology, Suppl. 1: Lasers, CRC Press, Boca Raton, FL (1991), p. 3. Hanna, D. C. and Jacquier, B., Eds., Miniature coherent light sources in dielectric media, Opt. Mater. 11, Nos. 2/3 (1999). Kaminskii, A. A., Crystalline Lasers: Physical Processes and Operating Schemes, CRC Press, Boca Raton, FL (1996). Kaminskii, A. A., Laser Crystals, Their Physics and Properties, Springer-Verlag, Heidelberg (1990). Moulton, P., Paramagnetic Ion Lasers, in Handbook of Laser Science and Technology, Vol. I: Lasers and Masers, CRC Press, Boca Raton, FL (1995), p. 21 ©2001 CRC Press LLC 1.1.2 Host Crystals Used for Transition Metal Laser Ions Table 1.1.6 Host Crystals Used for Transition Metal Laser Ions Crystal Ti 3+ V 2+ Cr 2+ Cr 3+ Cr 4+ Mn 5+ Fe 2+ Co 2+ Ni 2+ Oxides Al 2 O 3 • • Ba 3 (VO 4 ) 2 • BeAl 2 O 4 • • BeAl 6 O 10 • Be 3 Al 2 Si 6 O 18 • CaGd 4 (SiO 4 ) 3 O • CaY 2 Mg 2 Ge 3 O 12 • Ca 2 GeO 4 • Ca 3 Ga 2 Ge 3 O 12 • Ca 3 Ga 2 Ge 4 O 14 • Gd 3 Ga 5 O 12 • Gd 3 Sc 2 Al 3 O 12 • Gd 3 Sc 2 Ga 3 O 12 • La 3 Ga 5 GeO 14 • La 3 Ga 5.5 Nb 0.5 O 14 • La 3 Ga 5.5 Ta 0.5 O 14 • La 3 Ga 5 SiO 14 • LiNbGeO 5 • Mg 2 SiO 4 • MgO • ScBO 3 • ScBeAlO 4 • Sr 3 Ga 2 Ge 4 O 14 • SrGd 4 (SiO 4 ) 3 O • YA1O 3 • Y 2 SiO 5 • Y 3 Al 5 O 12 • • Y 3 Ga 5 O 12 • Y 3 Sc 2 Al 3 O 12 • Y 3 Sc 2 Ga 3 O 12 • ZnWO 4 • Halides CsCaF 3 • KMgF 3 • • ©2001 CRC Press LLC Table 1.1.6—continued Host Crystals Used for Transition Metal Laser Ions Crystal Ti 3+ V 2+ Cr 2+ Cr 3+ Cr 4+ Mn 5+ Fe 2+ Co 2+ Ni 2+ KZnF 3 • • LiCaAlF 6 • LiSrAlF 6 • • LiSrCrF 6 • LiSrGaF 6 • MgF 2 • • MnF 2 • Na 3 Ga 3 Li 3 F 12 • SrAlF 5 • ZnF 2 • Chalcogenides CdMnTe • ZnS • ZnSe • • Phosphide n-InP • 1.1.3 Host Crystals Used for Lanthanide Laser Ions Table 1.1.7 Host Crystals Used for Divalent Lanthanide Laser Ions Crystal Sm 2+ Dy 2+ Tm 2+ Halides CaF 2 • • • SrF 2 • • Table 1.1.8 Host Crystals Used for Trivalent Lanthanide Laser Ions Crystal Ce 3+ Pr 3+ Nd 3+ Sm 3+ Eu 3+ Dy 3+ Ho 3+ Er 3+ Tm 3+ Yb 3+ Oxides Al 2 (WO 4 ) 3 • Ba 0.25 Mg 2.75 - Y 2 Ge 3 O 12 • Ba 2 MgGe 2 O 7 • ©2001 CRC Press LLC Table 1.1.8—continued Host Crystals Used for Trivalent Lanthanide Laser Ions Crystal Ce 3+ Pr 3+ Nd 3+ Sm 3+ Eu 3+ Dy 3+ Ho 3+ Er 3+ Tm 3+ Yb 3+ Oxides BaGd 2 (MoO 4 ) 4 • BaLaGa 3 O 7 • Ba 2 NaNb 5 O 15 • Ba 2 ZnGe 2 O 7 • Ba 3 LaNb 3 O 12 • Bi 4 Ge 3 O 12 • • • Bi 4 Si 3 O 12 • Bi 4 (Si,Ge) 3 O 12 • Bi 12 SiO 20 • Ca 0.25 Ba 0.75 - (NbO 3 ) 2 • CaAl 4 O 7 • • CaGd 4 (SiO 4 ) 3 O • CaLa 4 (SiO 4 ) 3 O • CaMg 2 Y 2 Ge 3 O 12 • CaMoO 4 • • • Ca(NbO 3 ) 2 • • • • Ca(NbGa) 2 - Ga 3 O 12 • CaSc 2 O 4 • CaWO 4 • • • • • CaYAlO 4 • CaY 2 Mg 2 Ge 3 O 12 • • CaY 4 (SiO 4 ) 3 O • • • Ca 2 Al 2 SiO 7 • • Ca 2 Ga 2 Ge 4 O 14 • Ca 2 Ga 2 SiO 7 • Ca 3 Ga 2 Ge 3 O 12 • • Ca 3 Ga 2 Ge 4 O 14 • Ca 3 Ga 2 SiO 7 • Ca 3 Ga 4 O 9 • Ca 3 (Nb,Ga) 2 - (Ga 3 O 12 • Ca 3 (NbLiGa) 5 O 12 • Ca 3 (VO 4 ) 2 • Ca 4 GdO(BO 3 ) 3 • Ca 4 La(PO 4 ) 3 O • ©2001 CRC Press LLC Table 1.1.8—continued Host Crystals Used for Trivalent Lanthanide Laser Ions Crystal Ce 3+ Pr 3+ Nd 3+ Sm 3+ Eu 3+ Dy 3+ Ho 3+ Er 3+ Tm 3+ Yb 3+ CeP 5 O 14 • CsLa(WO 4 ) 2 • CsNd(MoO 4 ) 2 • ErAlO 3 • • • ErVO 4 Er(Y,Gd)AlO 3 • • Er 2 O 3 • Er 2 SiO 5 • • • Er 3 Al 5 O 12 • Er 3 Sc 2 Al 3 O 12 • Ga 3 Al 5 O 12 • GdAlO 3 • • • • GdGaGe 2 O 7 • GdP 5 O 14 • GdScO 3 • GdVO 4 • • Gd 2 (MoO 4 ) 3 • Gd 2 (WO 4 ) 3 • Gd 2 O 3 • Gd 3 Al 5 O 12 • • Gd 3 Ga 5 O 12 • • • • Gd 3 Sc 2 Al 3 O 12 • • • Gd 3 Sc 2 Ga 3 O 12 • • • HfO 2 -Y 2 O 3 • Ho 3 Al 5 O 12 • Ho 3 Ga 5 O 12 • Ho 3 Sc 2 Al 3 O 12 • KEr(WO 4 ) 2 • KGd(WO 4 ) 2 • KGd(WO 4 ) 2 • • • • KLa(MoO 4 ) 2 • • • KLu(WO 4 ) 2 • • KNdP 4 O 12 • KY(MoO 4 ) 2 • KY(WO 4 ) 2 • • • • K(Y,Er)(WO 4 ) 2 • • K 3 (La,Nd)(PO 4 ) 2 • K 5 Bi(MoO 4 ) 4 • [...]... )3 F Sr5 (VO4 )3 Cl Sr5 (VO4 )3 F Chalcogenides La 2 O 2 S ©2001 CRC Press LLC • 1.1.4 Tables of Transition Metal Ion Lasers Table 1.1.9 Transition Metal Ion Lasers Optical pump AL ArL D DL ErLYF ErYAG Hg KrL NdGL NdL NdYAG NdYLF NdYAP RL RS TiS TmYAP TmHoYAG W Xe — — — — — — — — — — — — — — — — — — — — Mode of operation AML — actively mode-locked cw — continuous wave p — pulsed qcw — quasi-continuous... CaF2 -CeF3 CaF2 -GdF 3 CaF2 -HoF 3 • • • • • • • • • • • • • • CaF2 -HoF 3 -ErF 3 CaF2 -LaF 3 CaF2 -NdF 3 CaF2 -ScF3 CaF2 -SrF2 CaF2 -SrF2 -BaF2 YF3 -LaF 3 CaF2 -YF 3 CaF2 -YF 3 -NdF 3 CdF 2 CdF 2 -CeF3 CdF 2 -GaF 3 CdF 2 -GdF 3 CdF 2 -LaF 3 CdF 2 -LuF 3 CdF 2 -ScF3 CdF 2 -YF 3 CdF 2 -YF 3 -NdF 3 CeCl 3 CeF3 CsGd 2 F7 CsY 2 F7 • • • • • • • • • • • • • • • • • • • • • ErF 3 -HoF 3 • ErLiF 4 GdF 3 -CaF2... KYF 4 Eu3+ D y 3+ Ho 3+ Er3+ Tm 3+ • KY 3 F10 Sm 3+ • • • • K 7 YF 5 K 5 (Nd,Ce)Li2 F10 K 5 NdLi 2 F10 LaBr 3 LaCl3 (La,Pr)Cl3 LaF 3 • • • • • • • • • LaF 3 -SrF2 LiCaAlF 6 • • • LiErF 4 • LiGdF 4 • LiHoF 4 • • • • • LiKYF 5 LiLuF 4 LiSrAlF 6 LiYF 4 • • • • • Li(Y,Er)F4 LiYbF 4 • • • • • • • • • • MgF 2 MnF 2 α-NaCaCeF 6 α-NaCaErF6 α-NaCaYF6 • • Na 0.4 Y 0.6 F2.2 PbCl 2 PrCl 3 PrF 3 SrF2 • • • • SrF2 . 1.1.4–1.1.8. The success of many of the schemes depends upon the degree of resonance of energy transfer transitions and the rate of nonradiative transitions. CRC Press LLC 1.1.4 Tables of Transition Metal Ion Lasers Table 1.1.9 Transition Metal Ion Lasers Optical pump Mode of operation AL — alexandrite