DEVELOPMENT OF GLASSES MEDIUM DOPED NEODYMIUM IONS (Nd3+) FOR LASER GAIN MEDIUM

• Main Author: RAJAGUKGUK (NIM : 30212006), JUNIASTEL
• Format: Dissertations
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/22736
• Institution: Institut Teknologi Bandung

Development of laser gain medium based on glass material was the most popular topic and continuously investigated especially in field of optics and lasers. In this study reported the synthesis of glass medium doped by Nd3+active ions to be applied as a glass laser medium operating at near infrared range. The aim of this research was establish the glass medium by inserting of Nd3+ ion into a host matrix glass and observe the physical properties, structure and optical medium. In addition, this study aims to design an optical pumping system based on laser diode to observe the luminescence spectra of the glass medium that developed in the near infrared range. The final stage of this research was to observe the possibility of the lasing produced by Nd:Glass medium with signal reference locked method at wavelength of 1064 nm. <br /> <br /> <br /> Host matrix that was developed in this study based on borate and phosphate glasses with each formula are (65-x)B2O3-15Na2O-10PbO-5ZnO-5Li2O -xNd2O3 (with x = 0,0; 0,05; 0,1; 0,5; 1,0; 2,0 and 4,0 mol%) and (50-x)P2O5-8Al2O3-12Na2O-10KF-10CaO -10CaF2-xNd2O3 composition (with x = 0,0; 0,5; 1,0; 1,5 and 2,0 mol%). Melt-quenching method with temperature melting at 1200oC was used to prepare Nd3+ ion doped glasses. <br /> <br /> <br /> Several observations and measurements of the glasses were carried to obtain information related to the structure of glasses, optical and radiative properties. Refractive index (n) and density (symbol) of each glass sample is performed by using an Atago refractometer and Archimedes principle respectively. The characteristic of the glass structure is also known from measurements using X-Ray Difractometer (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). Optical properties, such as absorption band, optical energy band gap and emission band for each glass was observed by using UV-Vis-NIR spectrophotometer and Quanta Master (QM-300) spectrofluorophotometer from Photon Technology International (PTI)-Horiba. From the results of optical properties measurement can be known some parameters like absorption spectra, emission spectra, oscillatroe strength (f), spectroscopic intensities ((symbol) 2, (symbol) 4 dan (symbol) 6), radiative transition probability (AR), branching ratio (symbol r), lifetime (symbol), emission cross section (symbol e) and quantum efficiency (symbol). From the absorption spectra measurements for Nd:Borat and Nd:Fosfat have been obtained absorption band transition almost similar at 4I9/2 symbol 4D3/2; 2P1/2; 2G9/2+4G11/2; 4G7/2; 2G7/2+ 4G5/2; 2H11/2; 4F9/2; 4F7/2; 4F5/2 dan 4F3/2. However, for Nd:Phosphate glass medium appears the new transition 4I9/2 symbol 4D7/2+2I13/2 at position of 329 nm wavelength. This occurs on the glass samples with the Nd3+ concentration at 1.5 mol.% (PANCaFN3) and 2,0 mol.% (PANCaFN4) respectively. Both types of glass also shows the hypersensitive transition that is located at symbol = 582 nm which is assigned to 4I9/2 symbol 2G7/2+ 4G5/2. It is claimed that the ions in the host matrix can absorb maximum light at a wavelength of 582 nm for the excitation of electrons from the lower level to a higher level. <br /> <br /> <br /> From the emission spectra of Nd:Borat and Nd:Fosfat glasses have been obtained three emission bands at 904 nm, 1064 nm and 1330 nm where these bands are assigned to the transitions 4F3/2( symbol) 4I9/2, 4F3/2 (symbol) 4I11/2 and 4F3/2 (symbol) 4I13/2 respectively. From three transitions above, the maximum emission band can be produces by 4F3/2 (symbol) 4I11/2 transition. It was shown that the glass medium that developed in this research can be applied as laser medium to obtain of light at near infrared (NIR) range. <br /> <br /> <br /> Moreover the optical pumping experiments based on 805 nm laser diode was designed to observe the luminescence spectra produced by both of glasses, Nd:Borate and Nd:Phosphate. Consistently, the luminescence spectrum intensity of the Nd:Phosphate glass medium is higher than Nd:Borat glass. However the luminescence peak position was slightly shifts, especially on 4F3/2 (symbol) 4I11/2 transition for 9 nm. This is due to (an increase in vibration coupling between the ions in the host matrix, causing non coherent for each photon when dropped from an excited state to the metastable state and continues during emission process. Further, based on the experimental of the laser signal amplification at 1064 nm is obtained that Nd:Phosphate and Nd:Borate glasses were capable amplifies the 1064 nm reference signal. Special for Nd:Phosphate glass, the maximum gain is obtained 3.69 dB by PANCaFN2 glass. Whereas, for Nd:Borate glass can produce maximum gain 2,03 dB generated by BNPZLiN4 glass. From the gain value of the glasses medium indicating that the most likely glasses developed in this work could generate lasing at 1064 nm wavelength region.