Organic semiconductors play a very important role in today’s high technology applications viz. optical imaging, optical switchng, optical computing, data storage, photodynamic therapy, dynamic holography, frequency mixing, harmonic generation and optical communications [1–4]. Among the organic semiconductors the phthalocyanines (Pc), naphthalocyanines (Nc) and porphyrines (PP) are of special significance because of their inexpensiveness, thermal and environmental stability, non toxicity as well as excellent optical and electronic properties. A combination of these features makes them an important class of photo-electronic materials for applications in various optoelectronic devices. Moreover, because of their excellent optical absorption efficiency in the red or NIR region they can be effectively utilized as a laser dye also. Most of the studies reported so far discuss the optical characterization of these organic semiconductors either in thin films, crystals, vapor or other solvents [4] whereas no work has been made to study the optical properties of these molecules in solid matrices especially work has been made to study the optical properties of these molecules in solid matrices especially a glassy matrix. Except for some studies in certain organic glassy matrices [5] only a limited amount of work has been done in organic matrices also. Recently our group has synthesized borate glassy matrices doped with metalatted phthalocyanines and rare earth doped phthalocyanines and studied their optical absorption characteristics [6, 7] The purpose of the present communication which is a continuation of the earlier work is to study the stimulated emission characterstics of metalatted phthalocyanine molecules in borate glass matrix with the intention of using them as efficient active media for solid state lasers. All the glass samples were prepared by the well known rapid quenching technique [8]. Reagent grade boric acid (H3BO3) and doubly sublimed phthalocyanines have been used as the starting materials for the preparation of the glass samples. The weighed quantities of the starting materials for 18 gm of glass were mixed homogeneously using an agate mortar. The batch was then placed in a silica crucible and heated in an electric muffle furnace. A slow heating was initially maintained until the temperature reached 80 ◦C and decomposition of H3BO3 to B2O3 was complete. The temperature was then rapidly increased to 120 ◦C so as to obtain a bluish melt. The melt was retained for about 10 min and then rapidly quenched by placing in between two well polished preheated brass plates so as to obtain glass discs of about 3 mm thickness and with a diameter of about 2 cm. The glass discs thus obtained were annealed at a temperature of about 60 ◦C and subsequently polished with water free lubricants. All the samples were obtained with very good transparency and appeared to be of good optical quality. Glass rods of length 8 cm, having diameter of 2 cm were also developed by heating the starting chemicals in 75 cm long borosil glass tubes after providing the necessary vacuum using a rotary pump. To remove the water vapor originating as a result of the decomposition of H3BO3 a vacuum trap was provided in between the rotary inlet and the sample tube. The tube was kept in a 1 m long vertical heater, the temperature of which can be controlled externally. After melting, the heater was switched off and the melt allowed to cool to room temperature by keeping it inside the heater itself. Finally the tube was taken out and glass rod removed by breaking the glass tube. The amorphous nature of the glass samples were confirmed by X-ray diffraction spectra recorded on a Shimadzu X-ray diffractometer with Ni filtered Cu Kα radiation. The absorption spectra were recorded in the UV-VIS-NIR region with a Hitachi U-2000 spectrophotometer. All the emission spectra were recorded at room temperature using a SPEX spectrofluorimeter with a wavelength resolution of ±0.2 nm. In all the fluorescence measurements the samples were excited at two wavelengths viz. 330 nm (corresponding to B band) and 700 nm (corresponding to Q band). Figs 1 to 8 show the fluorescence spectra of various Pc doped glassy matrices. All the other spectral data viz. emission wavelength, fluorescence bandwidth, relative fluorescence intensity, decay time and stimulated emission cross section are summarized in Table I. If we plot the absorption spectra of all these samples [6] and the corresponding emission spectra in the same plot it can be easily noted that the fluorescence spectra is almost the mirror image of the absorption lineshape as is observed in other matrices viz. crystals, vapors and other solvents [9–11]. Because of this “mirror image fluorescence” we can apply the Stickler-Berg formula [12] for evaluating the fluorescence decay time (τ ) and the expression is given by