The future of exoplanet detection lies in the mid-infrared (MIR). The MIR region contains the blackbody peak of both hot and habitable zone exoplanets, making the contrast between starlight and planet light less extreme. It is also the region where prominent chemical signatures indicative of life exist, such as ozone at 9.7 μm. At a wavelength of 4 μm the difference in emission between an Earth-like planet and a star like our own is 80 dB. However a jovian planet, at the same separation exhibits 60 dB of contrast, or only 20 dB if it is hot due to its formation energy or being close to its host star. A two dimensional nulling interferometer, made with chalcogenide glass, has been measured to produce a null of 20 dB depth, limited by scattered light. Measures to increase the null depth to the theoretical limit of 60 dB are discussed.
We prepared numbers of GeAsSe glasses and investigated their thermal stability and optical properties in order to search the best glasses with relatively high glass transition temperature Tg, strong structural stability, low optical loss and high optical nonlinearity. Through our systematical measurements, we concluded that the glasses with a mean coordination number around 2.45-2.5 are the best for the applications in photonics with Tg of 450K, low optical loss of 0.2dB/cm, high optical nonlinearity 7.5×10-14cm2/W and less photosensitivity.
The signal intensity and spectrum of electron-spin resonance (ESR) has been observed in silicon nanowires (SiNW's)
and nano-crystalline silicon structure based on JEOL system model FA-100 at around 9.4GHz, microwave modulation
frequency was stabilized at 100KHz. The over-saturation behaviors of signal intensity of ESR in different diameters of
SiNW's by observing the microwave power and analyzing the oxidation related, room temperature (RT) and 77K
dependences of ESR spectrum in different magnetic fields and microwave powers have been ascribed that they come
from the different defects. The defects have existed in silicon-based materials using physical behaviors of the signal
intensity of ESR we have obtained because of the influence of temperature dependences, different microwave powers
and oxidized sample for SiNW's.