E-O Q Crystal

E-O Q Crystal

LiNbO3

LiNbO3 is widely used as  electro-optic modulator and Q-switch for Nd:YAG, Nd:YLF and Ti:Sapphire  lasers as well as modulator for fiber optics, etc. The transverse  modulation is mostly employed for LiNbO3 crystal.

If the light propagates in  z-axis and electric field applies to x-axis, the refractive retardation  will be G = p Lnr22V/ l d. The electro-optic coefficients of LiNbO3 are:
r 33 = 32 pm/V, r 31 = 10 pm/V, r 22 = 6.8 pm/V at low frequency
r 33 = 31 pm/V, r 31 = 8.6 pm/V, r 22 = 3.4 pm/V at high electric frequency.

MgO:LiNbO3 and ZnO: LiNbO3 crystals have similar electro-optic properties to LiNbO3 but with higher damage threshold. 
The refractive index of an optical medium is altered by the presence of  sound, this is called acousto-optic effect which can be used in many  devices include optical modulators, switches, deflectors, filters,  frequency shifters and spectrum analyzers. JH Optek provide several  kinds of acousto-optic crystals: LiNbO3 SAW wafers, LiTaO 3 SAW wafers.  TeO 2 and PbMnO 4 crystals.

KTP Crystal

KTP has promising E-O and  dielectric properties comparable to those of LiNbO3, which makes it  extremely useful to various E-O devices. The following table gives the  comparison of KTP and those commonly used E-O modulator materials:

When these properties are  combined with high damage threshold, low optical loss at high average  power, wide optical bandwidth, thermal and mechanical stability, KTP  crystals are expected to replace LiNbO3 crystals as E-O modulators,  especially for mode-locking diode laser pumped Nd:YAG and Nd:YLF lasers  as well as Ti:Sapphire and Cr:LiSrAlF 6 lasers.

LiTaO3

LiTaO3 crystal is also  widely used E-O crystal, due to its optical, NLO and E-O properties  similar to those of LiNbO3 crystal, but with higher damage threshold  (> 500 MW/cm 2 for ns pulsed).

Properties

Transparent Range: 0.4 - 5.0 µm; 
E-O Coefficient: r 33 =30.4;
Refractive Indices: n o =2.176, n e =2.180 @ 633 nm.

Capabilities:

Diameter: f 40mm ~ f 102mm
Length: 50mm ~ 150mm
Orientation: X, Z, 36°Y, 42°Y, 128°Y

Polish: 0.016 m m

Wafers:

·         Diameter: f 40mm ~ f 102mm

·         Length: 0.2~1.2mm

·         Orientation: X, Z, 36°Y, 42°Y, 128°Y

·         Flatness: 
<10mm for f 40 ~ 65mm
<15mm for f 65 ~ 102mm

·         Bow:
<20mm for f 40~ 65 mm
<40mm for f 65 ~102mm

Slices:

·         Size: 100x45x1.5mm ~ 120x40x2mm

Parameter of LN and LT

Part Name: ------------LiNbo3 ------------LiTaO3
Crystal Class: -------Trigonal -------------Trigonal
Point Group:---------------3m------------------- 3m
Space Group: --------------R3c ----------------R3c
Lattice Point: ----a:0.5148 c:1.3863 --------a:0.5154c:1.3784
Melting Point: -----------1250 ---------------------1650
Density: -------------------4.64 ---------------------7.46
Curie Temp: ---------------~1160 --------------------~607M
Hardness:---------------------5-------------------------- 5.5
Dielectric Coefficient; -e 11/E0:85 e 33/E0:29.5--------- e 11/E0:51.7 e33/E0:44.5
Elastic Stiffness ----------CE11:2.04 ---------------CE11:2.33
Coefficient:(x10 -11 C/m2) -------CE11:2.46 -------CE11:2.77
Piezoelectric Stresses --------d22:2.04 -------------d22:2.4
Coefficient (x10 -11 C/N) --------d22:19.22 -----------------d22:0.8

BBO Crystal

BBO is an outstanding  crystal for many applications in nonlinear optics and electro-optics.  BBO is a colorless trigonal uniaxial crystal with low hygroscopic  susceptibility. Its transparency range is from 0.19m to 3.5m.

BBO is an efficient  nonlinear crystal for second, third, fourth and fifth harmonic  generators of Nd: Laser, dye lasers and ultrafast Ti:Sapphire lasers. It  has also excellent performance in optical parametric amplifier,  oscillators, etc.

Ultra thin BBO Plate

The minimum thickness of  BBO we can polish is 0.005mm, the ultra thin BBO is used for frequency  conversion of ultra fast laser with femtosecond pulse width. For  frequency conversion of ultrafast lasers such as Ti:sapphire and Dye  laser with femtosecond pulse width.
The main concern is fs pulse broadening induced by group velocity  mismatching(GVM) or group velocity dispersion. The suggested thickness  of BBO crystals is less than pulse width divides.

Phase matching angle

The phase matching angle is  depended on different applications of frequency conversion. The  familiar phase matching angles are listed below.

If you are not sure to calculate the phase matching angles, please contact us for assistance.

BBO Optical properties

BBO Physical properties:;

We can provide as large as 10x10x25mm BBO for high power application.