Abstract: A method for producing of ultra-clean and High-purity electronic grade reagents is disclosed. The industrial grade reagents are chemically pretreated and filtered, and the colature is rectified. Heating the steam during the rectification to overheated steam, and filtering the overheated steam used the microporous membrane to remove the solid particulates. Condensing the overheated steam and the secondarily filter to remove the dust in the product. Due to the adoption of the technical scheme, the ultra-clean and High-purity isopropanol produced is in conformity with standard SEMI-C12 and the hydrochloric acid to standard SEMI-C8. And the method is applicable for the large-scale continuous production.

Abstract: Methods and systems for receiving an optical signal using cascaded frequency offset estimation. Coherently detecting an optical signal includes compensating for a coarse laser frequency offset between a transmitting laser and a local oscillator laser by determining a maximum phase error (MPE) in the optical signal, compensating for a residual laser frequency offset between the transmitting laser and the local oscillator laser, and decoding data stored in the optical signal.

Abstract: An inventive method for multi-symbol polarization switching for differential detection optical systems includes modulating a laser source by a DQPSK modulator, driving the DQPSK modulator with a data block configured for generating multi-symbol polarization-switched DQPSK differential-encoded signals, and polarizing the multi-symbol polarization-switched DQPSK signals with a polarizing modulator whose modulation speed is based on how often polarization states vary, wherein the data block provides a bits manipulation to provide the multi-symbol polarization switching thereby enabling differential detection for recovering correct original data by a receiver.

Abstract: An inventive method for coherent interleaved polarization-multiplexing PolMux optical communications with a single IQ modulator includes modulating a light source to generate a 50% return-to-zero RZ signal pulse at a frequency Rs, driving a single IQ modulator with inphase I and quadrature phase Q data at a bit rate of sais Rs to introduce phase modulation on said 50% RZ signal pulse to produce a QPSK pulse signal with all symbols being in a same polarization state without any time overlapping; and polarization modulating said QPSK signal to alternatively convert said QPSK signal into two orthogonal polarizations states enabling an interleaving PolMux signal with a symbol rate of Rs/2.

Abstract: An optical method for generating an optical quadrature duobinary QDB signal includes receiving a quadrature phase-shift-keying QPSK signal, and adding a delay to the received quadrature phase-shift-keying QPSK signal to generate an optical quadrature duobinary signal.

Abstract: A method for optical chirp-free optical polarization modulation includes dividing a data modulated optical signal into a first optical path and a second optical path, using a Mach-Zehnder intensity modulator in the first optical path for imparting a ? phase difference between adjacent symbols of the data modulated optical signal in the first optical path, adjusting a delay and amplitude of symbols of the data modulated optical signal in the second path so that the symbols in the first path and the symbols in the second path are synchronized and have substantially equal power levels, and combining the first and second optical paths so that symbols from the first and second optical paths are in orthogonal polarizations.

Abstract: Methods and systems for soft-decision non-binary low-density parity-check (LDPC) coding for ultra-long-haul optical transoceanic transmissions are provided. A receiver includes one or more maximum a posteriori (MAP) equalizers configured to decode one or more symbols of an encoded input stream to provide one or more symbol log-likelihood ratios (LLRs). One or more LLR estimators are configured to estimate the log-likelihood ratios of the one or more symbol LLRs to provide one or more bit LLRs. One or more non-binary LDPC decoders are configured to decode the input stream using the one or more bit LLRs to recover an original input stream.

Abstract: A method for producing of ultra-clean and High-purity electronic grade reagents is disclosed. The industrial grade reagents are chemically pretreated and filtered, and the colature is rectified. Heating the steam during the rectification to overheated steam, and filtering the overheated steam used the microporous membrane to remove the solid particulates. Condensing the overheated steam and the secondarily filter to remove the dust in the product. Due to the adoption of the technical scheme, the ultra-clean and High-purity isopropanol produced is in conformity with standard SEMI-C12 and the hydrochloric acid to standard SEMI-C8. And the method is applicable for the large-scale continuous production.

Abstract: Methods and systems for receiving an optical signal using cascaded frequency offset estimation. Coherently detecting an optical signal includes compensating for a coarse laser frequency offset between a transmitting laser and a local oscillator laser by determining a maximum phase error (MPE) in the optical signal, compensating for a residual laser frequency offset between the transmitting laser and the local oscillator laser, and decoding data stored in the optical signal.