The optical properties of rare earth ions are very interesting. Nevertheless, solid state laser materials such as doped glasses and crystal. The 4f electron shell determines the optical properties of rare earth ions; it is almost insensitive to the surrounding atom of the host environment because of transmission by 5s and 5p electron shells.

Among the rare earth ions, the Dy3+ ion is
one of the best appropriate player for analyzing the energy-efficient
luminescent materials [1, 2].  In contrast,
Dysprosium rare earth atoms, Dy which have an active unfilled f shells
in its electronic configuration ([Xe] 4f104s2),
can provide 1.3 ?m emission due to the 6F11/2, 6H9/2?6H15/2
transition [3]. In
addition, Dy has a good absorption band at approximately 800 nm, at which level
a cheap commercial laser diode could be used for excitation.

Conversely, the physical structure of amorphous selenium
(a-Se). For a long time, the structure of amorphous selenium was assumed to
contain a random mix of selenium chains (Sen) and 8-ring structures
(Se8) distributed randomly throughout the solid.  The filled lone pair (LP) p of
Selenium states forms the bonding (s) band while the empty anti-bonding p states
form anti-bonding (s*) band. The valence band of Se is formed from the lone
pair p electrons and the valence s states of Se lie far below the
top of the valence band [4]. During crystallization, the
chains of Sen and Se8 rings transforms into hexagonal and
monoclinic structure in sequence.

The latest achievements in the development of
chalcogenides doped rare earth ions (RE) studied in recent years for active
applications of photonic devices such as fiber amplifiers,  biosensors, optoelectronic chips, 3D optical
recording, luminescent labels, white light up-conversion emission, color
display and the near and mid-IR [5-9], The low phonon energy (<500 cm-1) and high refractive indices of chalcogenides glasses hosts bring about high quantum efficiencies for rare earth ions transitions and larger oscillator strengths of RE dopants [10,11].