Erbium and ytterbium co-doped phosphate glass has a broad application because of the excellent properties. Mostly, it is the best glass material for 1.54um laser due to its eyesafe wavelength of 1540 nm and high transmission through atmosphere. It's also suitable for medical applications where the need for eye protection may be difficult to manage or diminish or hinder essential visual observation. Recently it is used in optical fiber communication instead of EDFA for its more super plus. There is a great progress in this field.
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Properties
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Cr14
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EAT14
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WM4
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n d
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1.5393
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1.544
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1.536
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Density(g/cm 3 )
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3.10
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3.15
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2.83
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Center lasing wavelength(nm)
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1535
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Abbe value
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64
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65
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66
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Stimulated cross section (pm 2 )
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0.8
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0.8
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0.75
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Fluorescent lifetime (micro second)
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7.7
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9.0
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8.0
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Radiative lifetime (micro second)
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8.8
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9.1
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FWHM (nm)
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29
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|
45
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Transformation temp.(ºC)
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455
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442
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530
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Softening temp.(ºC)
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493
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470
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573
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a(25-80°C) (10 -7 /K)
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103
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82
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a(25-300°C) (10 -7 /K)
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127
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96
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dn/dT (10 -7 /K)
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-52
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-47
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-30
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dS/dT (10 -7 /K)
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3.6
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6.4
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14
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Coeff.of linear thermal expansion (10 -6 /ºC)(20~100ºC)
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|
10
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Non-linear refractive index coeff.n 2 (×10 － 13 e.s.u)
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1.20
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Weight loss at 100°C boiling water (mg/cm 2 .hr)
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70μg/hr.cm 2
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Specification of Er:Glass rod
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Dimension Tolerances
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Rods with diameter: ±0.025 mm , Length: ±0.5 mm
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Surface quality:
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10/5 Scratch / Digper MIL-O-1380A
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Parallelism:
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< 10 arc seconds
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Wavefront distortion :
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Lambda /8 per inch @ 633 nm
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Extinction Ratio:
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>25dB
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AR Coating Reflectivity
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< 0.25% @1540nm
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