On-chip optical isolation based on the magneto-optic nonreciprocal phase-shift effect has also been explored in the near-IR spectrum and may be extended to the MWIR for optical waveguide on-chip applications. Other approaches that may be used to create an unidirectional propagation of the light are based on nonlinear optical processes, in which a nonreciprocal response can be realized. For standard Faraday rotation approaches, polarizing elements in the IR range may need to be developed for isolation purposes. However, present materials systems and geometrical structures may need to be improved to avoid the need for cryogenic cooling and to deal with thermal lensing effects at high powers. Materials that exhibit very strong magneto-optic properties include Indium Antimonide (InSb) and Mercury Telluride (HgTe), both of which may be used in MWIR and LWIR. These devices may be polarization sensitive, typically for free space laser coupling, or polarization insensitive, which are used in fiber optics applications. Commercially available optical isolators are limited to the visible and near-IR spectra and are based on the magneto-optic effect (Faraday effect). An optical isolator is a device that is used for this purpose since it transmits light in a particular direction while blocking the light in the opposite direction. High-performance laser systems must be protected from unwanted back reflected light, which may destabilize the laser or even damage the internal laser cavity. Also, there is a need in developing MWIR high-power laser systems for electronic warfare (EW) applications, such as infrared countermeasures (IRCM), in which the laser sources may be spectrally or coherently combined in order to achieve the required performance. There are many military sensors applications that require optical isolation at 2 micron wavelength, such as Tm-doped high-power fiber laser systems. New military and sensing applications are expected to drive the IR laser market in the next few years."Mid-Infrared Lasers 2010"report published by Strategies Unlimited summarizes that the new market segments will grow approximately 30% per year, compounded annually through 2014. DESCRIPTION: The optical spectrum from Short Wave Infrared (SWIR) (1-2 micron) and Mid Wave Infrared (MWIR) (3-8 micron) to Long Wave Infrared (LWIR) (8-15 micron) is known for covert and eye-safe operation, for the thermal vibrations of molecules (used in sensing and thermal imaging), ladar applications, etc. OBJECTIVE: Identify, develop and demonstrate materials and techniques based on the magneto-optic effect or nonlinear processes, which can realize nonreciprocal response for optical isolation in Short-IR, Mid-IR, and Long-IR laser applications (2-15 micron).
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |