I. V. Bodnar

CuInSSe‐doped glass saturable absorbers for the passive mode‐locking of neodymium lasers

By using a CuInS2xSe2(1−x)‐doped glass as an intracavity saturable absorber, passive mode‐locking of Nd:YAG and Nd:YAlO3 lasers is obtained. Ultrashort laser pulses are achieved with duration of 16 ps (for Nd:YAlO3 at 1.08 μm) and 36 ps (for Nd:YAG at 1.064 μm), respectively. The intensity dependent transmittance and transient absorption change measurements are performed on CuInS2xSe2(1−x)‐doped glasses at 1.08 μm with the use of laser pulses of 15 ps width. The bleaching relaxation time is found to be ∼11 ps.

Crystal Structure and Optical Properties of CuInS2 Nanocrystals in a Glass Matrix

Glasses containing nanometer sized particles of CuInS2 (10 to 70 nm) were fabricated and characterized. The lattice structure of nanoparticles determined by X-ray diffraction is different from bulk CuInS2 that can provide features of optical properties of the glasses. This change of lattice is proposed as a possible reason for the low-energy shift of the fundamental absorption edge observed for nanoparticles as compared with bulk CuInS2.

Spectroscopic ellipsometry study of Cu2ZnSnSe4 bulk crystals

Using spectroscopic ellipsometry we investigated and analyzed the pseudo-optical constants of Cu2ZnSnSe4 bulk crystals, grown by the Bridgman method, over 0.8–4.5 eV photon energy range. The structures found in the spectra of the complex pseudodielectric functions were associated to E0, E1A, and E1B interband transitions and were analyzed in frame of the Adachis model. The interband transition parameters such as strength, threshold energy, and broadening were evaluated by using the simulated annealing algorithm. In addition, the pseudo-complex refractive index, extinction coefficient, absorption coefficient, and normal-incidence reflectivity were derived over 0.8–4.5 eV photon energy range.

Linear and nonlinear properties of ultrasmall CuInS2xSe2(1-x) particles in a glass matrix

Abstract We have studied nonlinear optical properties of CuInS2xSe2(1−x)-doped silicate glasses. The CuInS2xSe(1−x) particles had the size in the range of 10–30 nm and structured in the glass matrix as fractal aggregates. The transient change of absorption and intensity-dependent transmission under picosecond excitation have been investigated by means of pump-and-probe and single-beam techniques, respectively. We have observed both the bleaching and the induced absorption depending on intensity of excitation and the ratio of the band gap and pump photon energy. The effects observed have been discussed.

Spectroscopic ellipsometry study of Cu2ZnSnS4 bulk poly-crystals

The linear optical properties of Cu2ZnSnS4 bulk poly-crystals have been investigated using spectroscopic ellipsometry in the range of 1.2–4.6 eV at room temperature. The characteristic features identified in the optical spectra are explained by using the Adachi analytical model for the interband transitions at the corresponding critical points in the Brillouin zone. The experimental data have been modeled over the entire spectral range taking into account the lowest E0 transition near the fundamental absorption edge and E1A and E1B higher energy interband transitions. In addition, the spectral dependences of the refractive index, extinction coefficient, absorption coefficient, and normal-incidence reflectivity values have been accurately determined and are provided since they are essential data for the design of Cu2ZnSnS4 based optoelectronic devices.