Kewen K. Li

Optical amplification in Nd3+ doped electro-optic lanthanum lead zirconate titanate ceramics

As high as 13.0dB single-pass gain was obtained at 1064.4nm in a thin electro-optic ceramic plate of neodymium doped lanthanum-modified lead zirconate titanate (Nd:PLZT). Pumping with a diode laser, gains were achieved in 1.0 and 0.5mol% Nd ion doped samples over a broad seed laser power ranging from tens of nanowatts to tens of milliwatts at room temperature. The broad absorption spectra of Nd:PLZT made it insensitive to the pump wavelength. The Nd:PLZT had a total scattering loss coefficient of less than 0.06cm−1 and exhibited a considerable quadratic electro-optic coefficient greater than 0.30×10−16m2∕V2.

Lasing action and optical amplification in Nd 3+ doped electrooptic lanthanum lead zirconate titanate ceramics

Both single-pass gain and lasing action at 1064.4 nm were observed in ceramic gain media of neodymium doped lanthanum-modified lead zirconate titanate, which exhibits good electrooptic (EO) effect from visible through mid-wave IR band (400 nm to 5.5 µm). These works have removed roadblocks off the way leading to development of long envisioned multifunctional optical devices. The impact of the Nd3+ doping concentration on the EO effect in the Nd3+:PLZT ceramics was studied. The finding of the slowly trailing-off was satisfactorily explained with the rich vacancy-based carrier traps, which are responsible for the long persistent optoenergy storage.

Optical amplification in disordered electrooptic Tm3+ and Ho3+ codoped lanthanum-modified lead zirconate titanate ceramics and study of spectroscopy and communication between cations

Rare earth doped electro-optic (EO) ceramics of lanthanum-modified lead zirconate titanate (PLZT) are promising in building multifunctional optical devices, by taking advantage of both EO effect and optical activity. In this work, the combination of the measured spectra of absorption and photoluminescence, the fluorescent decay, the calculated Judd-Ofelt parameters, and measured single pass gain in Tm3+, Ho3+ codoped PLZT ceramics have marked them out as promising gain media in building electrically controllable lasers/optical amplifiers and other multifunctional devices. Optical energy storage was also observed in the optical amplification dynamics.

Low voltage, high repetition rate electro-optic Q-switch

A low voltage, high repetition rate electro-optic Q-switch using OptoCeramic/spl reg/ PMN-PT was developed. A solid-state laser with repetition rate as high as 200 KHz with switching voltage as low as 48 volts has been demonstrated.

Wavelength translation based on photoinduced broadband absorption in Nd3+ -doped lanthanum lead zirconate titanate ceramics.

A correlation between a photoinduced broadband absorption (BBA) and a strong long persistent optoenergy storage (LPOES), both evident in ceramic plates of neodymium-doped lanthanum-modified lead zirconate titanate (Nd:PLZT), has been proposed and verified experimentally. As a direct evidence of the suggested correlation, a 3.0 dB gain was obtained with a preilluminated Nd:PLZT plate by simply heating up the plate to 60 degrees C. Thermal history related gain profiles taken in an Nd:PLZT plate unveiled that the intrinsically rich carrier traps in the ceramics are highly responsible for the remarkable BBA and underlying LPOES, and hence thermal to near-IR wavelength translation.

Fast, widely tunable electro-optic Fabry-Perot filter

A fast tunable Fabry-Perot etalon was developed using high performance OptoCeramic/sup /spl trade// PMN-PT. The response time fast than 500 ns was demonstrated. A dual-cavity tunable filter was designed and built, with a tuning range greater than 100 nm.

Electroinduced broadband light emission in rare earth doped lanthanum lead zirconate titanate ceramics

A continuum light emission was observed in a Tm3+/Ho3+ codoped PLZT ceramic slab upon exposing to a corona atmosphere. The origin of the broad light emission may be rooted in an electroinduced structural variation.

Upconversion with Ho 3+ and Tm 3+ codoped lead lanthanum zirconate titanate ceramics

Using Ho³⁺ and Tm³⁺ codoped PLZT ceramic gain media, excellent upconversion was observed and investigated. A new model was proposed, leading ways towards upconversion-based laser and sensor development.