Er,Yb:Glass—Laser Glass

22 May 2019

Description

Er³⁺/Yb³⁺ co-doped phosphate glass — as the 1540nm eye-safe radiation sources pumped by LD which can emit eye-safe 1540nm laser radiation directly used in laser ranging finder and telecommunication communication

Er³⁺ emission transition occurs within this wavelength range corresponding to the ⁴I_13/2 →⁴I_15/2 . However, Er³⁺absorption itself is too weak to allow direct pumping and so, energy transfers are required. The most efﬁcient ones are given by Yb³⁺ ions under absorption from the ²F_7/2 → ²F_5/2transition, followed by energy transfer to the ⁴I_11/2 Er³⁺ level and fast nonradiative transition to the Er³⁺ ⁴I_13/2level which emits the expected ﬂuorescence.Er,Yb:glass laser with radiation output at the wavelength of 1540 nm does not require the addition of additional components.

As an eye-safe wavelength laser, 1540um ,Er³⁺/Yb³⁺ co-doped phosphate glass lasers have attracted much attention for their compactness and low cost, such as laser generation and signal amplification because the wavelength of 1540nm is just at the position of the eye-safe and the fiber optic communication window. 1540nm lasers have used in ranging finder, radar, target recognition. Er³⁺/Yb³⁺ co-doped phosphate glass cooperate with passive Q-Switch crystal -co:spinel to get 1540nm pulse solid-state laser.

Parameter

Laser Specifications

	EAT14	WM4
Cross section for stimulated emission (10-20cm2)	0.8	0.75
Fluorescent lifetime (ms)*	7.7-8.0	7.7-8.2
Center lasing wavelength (nm)	1535	1535

Optical Properties

	EAT14	WM4
Refractive index (1535nm)	1.524	1.528
Refractive index (d 589.3nm)	1.532	1.536
Abbe value	66	66
dn/dT (10-6/℃) (20~100℃)	-1.72	-3

Thermal Specifications

EAT14	WM4	WM4
Transformation temp. (℃)	556	530
Softening temp. (℃)	605	573
Coeff.of linear thermal expansion (10-7/K) (20~100℃)	87	82
Coeff.of linear thermal expansion (10-7/K) (100~300℃)	95	96
Thermal Coeff.of optical path length (10-6/K) (20~100℃)	2.9	1.4
Thermal conductivity (25℃) (W/mK)	0.7	0.7

Other Specifications

EAT14	WM4	WM4
Density (g/cm3)	3.06	2.83
Chemical durability (weigh loss rate at 100℃ distilled water) (μg/hr.cm2)	52	82

Absorption and Emission Spectrum

Polishing Specification

Orientation Tolerance	< 0.5°
Thickness/Diameter Tolerance	±0.05 mm
Surface Flatness	<λ/8@632 nm
Wavefront Distortion	<λ/4@632 nm
Surface Quality	10-5
Parallel	10〞
Perpendicular	15ˊ
Clear Aperture	>90%
Chamfer	<0.1×45°
Maximum dimensions	dia (3-12.7)×（3-150）mm2