Jean Wei

Measuring refractive index using the focal displacement method

A simple technique is introduced for measuring the refractive index of plane-parallel samples having thickness of the order of a millimeter. The refractive index values are reported for six bulk semiconductors, each index measured at two infrared wavelengths using this method. The values are found to be within a few percent of those in literature for four semiconductors. The other two semiconductors were newly grown ternary alloys (CdMgTe and CdMnTe), for which the refractive index values have not been reported previously at the wavelengths studied here.

Efficient Mid-Infrared Optical Parametric Oscillator Based on CdSiP 2

We report the first optical parametric oscillator based on the new mid-infrared nonlinear optical crystal CdSiP2. Pumping with a 2W, 1.99-micron Tm:YALO laser produced 340 mW average power output (signal + idler) at 27% slope.

Measurement of refractive indices of CdSiP 2 at temperatures from 90 to 450 K

Ordinary and extraordinary refractive indices of CdSiP2 were measured and a Sellmeier equation was obtained for the first time to our knowledge over the temperature range 90 to 450 K. The index values were used to calculate the crystal temperature and phase-matching angle dependence of the generated wavelengths in the nonlinear frequency conversion of a range of pump wavelengths. A good match was obtained between the calculated values of the wavelengths and some experimental measurements.

Measurement of the second order nonlinear optical coefficient of GaAs, GaP and InGaAs (Conference Presentation)

Orientation patterned GaAs and GaP crystals are increasingly being used for frequency conversion of laser beams into desired wavelengths. The ternary alloy InGaAs has smaller band gap energy compared to GaAs and is expected to have a nonlinear optical coefficient that is higher than that of GaAs. We will present the results of measurements of the second order nonlinear optical coefficient of InGaAs, along with recent measurements of GaAs and GaP obtained through second harmonic generation of a tunable carbon dioxide laser in the 9.2 to 10.6 μm range. The results will be compared to available values obtained at other wavelengths [1,2] Keywords: nonlinear optics, frequency conversion, second harmonic generation REFERENCES [1] T. Skauli, K. L. Vodopyanov, T. J. Pinguet, A. Schober, O. Levi, L. A. Eyres, M. M. Fejer, J. S. Harris, B. Gerard, L. Becouarn, and E. Lallier, G. Arisholm, “Measurement of the nonlinear coefficient of orientation-patterned GaAs and demonstration of highly efficient second-harmonic generation”, Optics Letters , Vol. 27, No. 8, 628, (2002) [2] I. Shoji, T. Kondo, A. Kitamoto, M. Shirane, and R. Ito, “Absolute scale of second-order nonlinear-optical coefficients”, J. Opt. Soc. Am. B, Vol. 14, No. 9, 2268, 1997

A semiconductor saturable absorber for mid-infrared wavelengths

Saturable absorption of nanosecond and picosecond duration pulses in a thin HgCdTe film is reported at 4.6 μm. The material shows promise as a mode locker for mid-infrared ultrafast lasers.