Doping Concentration Of Er3 Research Articles

Broad-band excitation mechanism for photoluminescence in Er-doped Ge 25Ga 1.7As 8.3S 65 glasses

Photoluminescence (PL) and photoluminescence excitation (PLE) spectroscopy have been carried out at both room temperature and at 5 K on a series of Er-doped GeGaAsS glasses with varying doping concentrations, ranging from 200 to 7400 ppm Er. It is found that increased Er doping concentration results in an increase in the strength of the broad band excitation of the Er 3+ atoms. In addition, at low temperatures, a direct link between the broad band excitation process and the host glass luminescence is observed. The increased strength of the broad band excitation of the Er 3+ dopants corresponds with a decrease in the intensity of the host glass luminescence in the more heavily doped samples. This is interpreted as a quenching of the host glass luminescence through an increase in the non-radiative transfer of energy from defect states in the glass to the Er dopants. This supports a previous hypothesis that the same native defect states in the glass are involved in both the host glass PL and the broad band PLE of the rare earth dopants. The implications of the current results for the understanding of luminescence properties in undoped chalcogenide glasses are discussed briefly.

Incorporation Of Er Into GaN By in-situ Doping During Halide Vapor Phase Epitaxy

ABSTRACTThe incorporation of Er into GaN by in-situ doping during halide vapor phase epitaxy has been investigated. The NH3, HCl, metallic Ga and Er were used as source materials, while N2 was employed as a carrier gas. The GaN:Er films were obtained at different Ga/Er source temperatures. The SIMS analysis shows that the steady state Er doping concentration can be as high as 2×1018 cm−3. All in-situ Er-doped samples luminescence at 1.54 μm due to the 4I13/2 → 4I15/2 transition of Er3+ at both low (11K) and room temperature. The higher the Ga/Er boat temperature, the stronger the 1.54 μm luminescence, implying a higher incorporation rate of Er into the GaN. The 4I11/2 → 4I15/2 transition luminescence, centered around 980 nm, can also be detected at both low and room temperature. The broad-spectrum PL measurements exhibited sharp bandedge luminescence without the presence of the yellow luminescence band.

Er/O and Er/F doping during molecular beam epitaxial growth of Si layers for efficient 1.54 μm light emission

Er, together with oxygen or fluorine as co-dopants, has been incorporated into Si during molecular beam epitaxial growth using co-evaporation of Si and Er containing compounds. The Er doping concentration using both Er2O3 and ErF3 can reach a level of ∼5×1019 cm−3 without precipitation, which is at least one order of magnitude higher than a previously reported solid solubility limit for Er in Si. Growth, structural, and luminescence characterization of these Er/O and Er/F doped Si samples are reported. In particular, 1.54 μm electroluminescence has been observed from Er/O doped Si layers at room temperature through hot electron impact excitation.

Observation of trap states in Er-doped InP by photoreflectance

We have investigated room-temperature photoreflectance (PR) spectra in Er-doped InP grown by low-pressure organometallic vapor phase epitaxy. A new feature is clearly observed at 1.31 eV, accompanied with a feature due to the bandgap transition at 1.35 eV. The new feature is attributed to a transition involving an Er trap. The transition energy is independent of both doping processing techniques and concentrations of Er in the layers. The PR spectral width of the trap transition energy described by the broadening parameter, increases linearly with the logarithm of Er concentrations.

Optical Fiber Amplifiers and Their Applications. High Power Er-Doped Fiber Amplifiers.

The Er-doped fiber amplifier allows direct optical amplification with high pump to signal optical conversion efficiency. The amplifier for a 1.551.tm optical signal is compactly composed of an Er-doped fiber and other optical components. Amplification properties of the amplifier are mainly dependent on the Er doping concentration, the co-dopant, the fiber length, and the performance of the pumping power source. An optimized fiber, for use within the optical amplifier, has a gain of 40dB and a conversion efficiency of 85% from the incident pumping power to the amplified signal power. Amplification properties also depend on the characteristics of the optical signals. This paper explains techniques of structuring high-power Er-doped fiber amplifiers and recent high-power amplifiers.

Er‐doped silica‐based planar ring resonator

AbstractA new configuration of a ring resonator is proposed by using an Er‐doped silica‐based waveguide. Its laser oscillation and variable finesse were realized. to determine the Er concentration suitable for the Er‐doped waveguide ring resonator, the Er concentration dependence of the threshold pump power for laser oscillation in an Er‐doped waveguide ring resonator is analyzed numerically. It was found that an optimum Er concentration is in the range of 0.3 fc 0.5 wt.%. Further, from the actual measurement, it is confirmed that the gain of the silica‐based waveguide with Er doping concentration in this range is larger than the loss of the ring resonator. Then, an optimum coupling condition of the directional coupler is studied. It is found that a maximum value of 91 percent is obtained as the coupling ratio at a wavelength of 1.533 μm for a coupling length of 1.0 mm. Based on these investigations, an Er‐doped waveguide ring resonator with a circumferential length of 9.2 cm is fabricated. As a result, an Er‐doped waveguide ring laser is realized that has an oscillation center wavelength of 1.533 μm, a threshold value of 93 mW for the pump power and a slope efficiency of 0.3 percent. the oscillation modes of the realized ring laser are longitudinal multimodes with its free spectral range (FSR) of 2.2 GHz. the narrow line characteristics of an average line width of 200 kHz are found. From the results of the transmission spectral measurement, it is confirmed that the Er‐doped waveguide ring resonator works as a stopband‐type optical frequency filter. In addition, it is found that the finesse can be varied by controlling the pump power. Maximum finesse is 36.