We report a systematic study of thermal effects in photonic crystal membrane lasers based on line-defect cavities. Two material platforms, InGaAsP and InP, are investigated experimentally and numerically. Lasers with quantum dot layers embedded in an InP membrane exhibit lasing at room temperature under CW optical pumping, whereas InGaAsP membranes only lase under pulsed conditions. By varying ...

Recently, the world's first room-temperature maser was demonstrated. The maser consisted of a sapphire ring housing a crystal of pentacene-doped p-terphenyl, pumped by a pulsed rhodamine-dye laser. Stimulated emission of microwaves was aided by the high quality factor and small magnetic mode volume of the maser cavity yet the peak optical pumping power was 1.4 kW. Here we report dramatic miniat...

Excited state lifetimes of C60/toluene solution and C60 films macromolecular were measured by pump-probe method. Relation between optical switching effect of material and pulse width of pumping field is briefly described. It is found that the faster switching speed of light is, the triplet state lifetime is shorter. A He-Ne laser, as a probe, passed through the sample in the pump-probe experime...

In this thesis, I study optical pumping as a powerful cooling tool for trapped ultra-cold atoms in a highly collisional regime. First application of optical pumping is a continuous loading scheme used to transfer atoms from a guided beam into a hybrid trap. Further, I introduce a Sisyphus cooling scheme based on radio-frequency transitions and optical pumping, operating simultaneously to the ac...

The Zeeman splittings of the hyperfine structure of rubidium as well as the ambient geomagnetic field are investigated by using an optical pumping apparatus. The frequencies of Zeeman transitions are proportional to the magnetic field applied; using this, the ambient geomagnetic field is found to be B = ((37.755±0.025)ex+(5.5179±0.0030)ey +(19.15±0.06st±0.67sy)ez) ·10−6 T, compared to an accept...

We have investigated a new radiation pressure trap which relies on optical pumping and does not require any magnetic field. It employs six circularly polarized divergent beams and works on the red of a Jg −→ Je = Jg + 1 atomic transition with Jg ≥ 1/2. We have demonstrated this trap with cesium atoms from a vapour cell using the 852 nm Jg = 4 −→ Je = 5 resonance transition. The trap contained u...

The work presented here is a study of thermally enhanced injection in light-emitting diodes (LEDs). This effect, which we refer to as "thermal pumping", results from Peltier energy exchange from the lattice to charge carriers when current is injected into an LED. For an applied voltage V such that qV < (hw), where q is the electron charge and (hw) is the average emitted photon energy, thermal p...

Polarized (3)He spin filters are needed for a variety of experiments with slow neutrons. Their demonstrated utility for highly accurate determination of neutron polarization are critical to the next generation of betadecay correlation coefficient measurements. In addition, they are broadband devices that can polarize large area and high divergence neutron beams with little gamma-ray background,...

The TRIUMF Neutral Atom Trap (TRINAT) has an active experimental program to measure angular correlations in the decay of spin-polarized K. An overview of our recent progress including a successful run in December 2012 is described in our other report. This report will focus on our progress in developing a better model of the optical-pumping process that polarizes the trapped atoms. Optical pump...