Caesium lithium borate

CsLiB₆O₁₀ (Caesium lithium borate, CLBO) is a non-linear crystal for UV applications and generates the 4th and 5th harmonics of the Nd:YAG fundamental laser wavelength (1064 nm).

Properties

• Transparency range : 180 nm - 2750 nm
• Symmetry : tetragonal, point group 4m2
• Cell parameters : a = 10.494, c = 8.939 Å
• Mohs hardness : 4
• Refractive indexes:
  • at 1064 nm : n_o= 1.4852; n_e = 1.4353
  • at 532 nm : n_o = 1.4985; n_e = 1.4462
  • Sellmeier equations (Range:of 400 - 2400 nm ; Ref: Proc. SPIE , 4453, 106 (2001))

    <math>n_o^2=2.2145+\frac{0.00890}{ \lambda^2 - 0.02051}-0.01413\lambda^2</math>

    <math>n_e^2=2.0588+\frac{0.00866}{ \lambda^2 - 0.01202}-0.00607\lambda^2</math>

• Non-linear coefficient at 1064 nm : d₃₆ = 0.86 pm/V
• Optical damage threshold : 25 GW/cm² (1064 nm; 1.1 ns pulses)
• Walk off:
  • at 532 nm : 1.83°
  • at 488 nm : 0.98°
• Cut off SHG : 471 nm
• Chemical properties : slightly hygroscopic

Nonlinear Optical Properties of CLBO

Harmonics wavelength (nm)	Phase-matching angle (°)	Calculated deff (pm/V)	Walk-off angle (°)	Angular bandwidth (mrad·cm)	Spectral bandwidth (nm·cm)	Temperature bandwidth (°C·cm)
266	61.6	0.84	1.83	0.49	0.13	8.3
213	67.3	0.87	1.69	0.42	0.16	5.1

Ref: Y. Mori, I. Kuroda, S. Nakajima, T. Sasaki, and S. Nakai, Appl. Phys. Lett. 67, 1818 (1995).
Y. Mori, Y. K. Yap, M. Inagaki, S. Nakajima, A. Taguchi, W. L. Zhou, and T. Sasaki, in Advanced Solid-State Lasers, Vol. 1 of Topics in Optics and Photonics (OSA, Washington, D.C., 1996), p. 341.

Applications

• generation highest harmonics (SHG, THG, 4HG, 5HG) of laser radiation Nd:YAG
• generation second, third lasers harmonics on the alexandrite, Ti:sapphire laser

Further reading

• D. Gerstenberger, T. Trautmann, and M. Bowers, "Noncritically phase-matched second-harmonic generation in cesium lithium borate ," Opt. Lett. 28, 1242-1244 (2003)