With the rising need for microfabricated chip-scale atomic clocks to enable high precision timekeeping in portable applications, there has been active interest in developing miniature (<few cm), chip-scale alkali vapor lamps, since vapor plasma discharge sources are currently the standard for optical pumping in double-resonance clocks. We reported in 2012 a first microfabricated chip-scale Rubi...

We studied cascaded optical rectification processes for intense terahertz (THz) pulse generation in electro-optic crystals using simulations based on one-dimensional coupled propagation equations of THz and optical fields. We found that under ideal conditions of perfect phase matching and no absorption, cascaded optical rectification processes produce intense THz pulses with efficiencies exceed...

Continuum generation from normally dispersive ultrahigh-numerical-aperture fibers deteriorates in relatively short times, limiting its application as a practical optical source for high-resolution optical coherence tomography. We find that reversible light-induced structural modification of fiber optic materials, rather than permanent optical damage, is responsible for this deterioration. By ex...

Using charge modulated electroabsorption spectroscopy (CMEAS), for the first time, the energy level alignment of a polymer:fullerene bulk heterojunction photovoltaic cell is directly measured. The charge-transfer excitons generated by the sub-bandgap optical pumping are coupled with the modulating electric field and introduce subtle changes in optical absorption in the sub-bandgap region. This ...

A strongly saturated waveguide-based optical-field-ionization soft-x-ray laser seeded by high harmonic generation was demonstrated for Ni-like Kr lasing at 32.8 nm. Compared with the same laser seeded only with spontaneous emission, seeding with high harmonics yields much smaller divergence, enhanced spatial coherence, and controlled polarization. The integration of high harmonic seeding, optic...

The ability to tune the Bragg wavelength of a fibre-Bragg grating (FBG) in an all-fibre laser can offer added functionality such as laser wavelength tunability, polarization selectivity, and Q-switching. Compared to current techniques which rely on mechanically straining the FBG to achieve Bragg-wavelength tunability, an all-optical technique for tuning an FBG offers potentially faster switchin...

Optical fiber taper waveguides are used to improve the efficiency of room temperature photoluminescence measurements of AlGaAs microdisk resonant cavities with embedded self-assembled InAs quantum dots. As a near-field collection optic, the fiber taper improves the collection efficiency from microdisk lasers by a factor of 15–100 times in comparison to conventional normal incidence free-space c...

We perform ray and wave simulations of passive and active spiral-shaped optical microcavities, comparing our results to experimental data obtained with mid-infrared quantum cascade spiral microlasers. Focusing on the angular emission characteristics, we find that both ray and wave simulations are consistent with the experimental data, showing richly-featured, multidirectional far-field emission...

An optically-pumped intersubband laser generator is proposed in which the continuum states above an A1 0.2Ga 0.8.4s GaAs A1 o2Ga o.sAs single quantum well with a width of L = 17 nm serve as the highest level in a four-level laser system. The design allows much greater flexibility in the choice of pumping source and simplifies considerabb the device fabrication. We have obtained the electronic s...

A 22× reduction in laser pump threshold and a 23× enhancement in energy conversion have been demonstrated on a second order distributed feedback (DFB) laser using a resonant optical pumping (ROP) technique. The ROP scheme couples the excitation light into a distinct resonant mode of the laser cavity through the illuminating at a specific resonant incident angle. Coupling excitation light into t...