Abstract: An integrated circuit spectrometer comprises a photonic circuit comprising: an optical input port for receiving light from a light source: and a filter array of filter elements, such as microring resonators, in optical communication with the optical input port. Each microring resonator is characterized by a different series of resonance wavelengths. If alternative filter elements are used, the filter elements may have different filter peaks to each other. The integrated circuit spectrometer also comprises a plurality of detectors, each of which is associated with one of said microring resonators to detect photons from an output of the microring resonator: and at least one processor configured to reconstruct, from signals received at the detectors, an input spectrum of the light received at the optical input port. The input spectrum may be reconstructed by an artificial neural network.

Abstract: A method of decoding a codeword that satisfies a k constraint into output data includes, using a decoder of a hard disk drive system, converting each bit of the codeword in Non-Return-to-Zero format, extracting, from the converted codeword, a plurality of data blocks comprising a first data block and a plurality of remaining data blocks, performing a first analysis on the plurality of data blocks for modifying each of the plurality of data blocks that satisfies a first predetermined criterion, and performing a second analysis on the plurality of data blocks after the first analysis for modifying each of the plurality of data blocks that satisfies a second predetermined criterion to obtain the output data.

Abstract: In the present disclosure, a method of operating a data storage apparatus is provided. The method includes writing a data signal into a portion of a data layer in a recording medium of a data storage apparatus. The method further includes determining a data layer coupling interference value arising due to interference from the data layer provided in between a sensor head and a servo layer of the recording medium in reading servo data, the data layer coupling interference value determined based on the data signal. The method further includes writing the data layer coupling interference value onto the recording medium. A corresponding data storage apparatus is provided.

Abstract: A method of decoding a codeword that satisfies a k constraint into output data includes, using a decoder of a hard disk drive system, converting each bit of the codeword in Non-Return-to-Zero format, extracting, from the converted codeword, a plurality of data blocks comprising a first data block and a plurality of remaining data blocks, performing a first analysis on the plurality of data blocks for modifying each of the plurality of data blocks that satisfies a first predetermined criterion, and performing a second analysis on the plurality of data blocks after the first analysis for modifying each of the plurality of data blocks that satisfies a second predetermined criterion to obtain the output data.

Abstract: A method of encoding an input data into a codeword that satisfy a k constraint includes partitioning the input data into a plurality of data blocks comprising a first data block and a plurality of remaining data blocks; performing a first analysis of the plurality of data blocks for modifying each of the plurality of remaining data blocks that satisfy a first predetermined criterion; performing a second analysis of the plurality of data blocks after the first analysis for modifying each of the plurality of data blocks that satisfy a second predetermined criterion; and converting each bit of the plurality of data blocks after the second analysis to produce the codeword in Non-Return-to-Zero (NRZ) format with the k constraint. There is also provided a method of decoding the codeword with satisfies the k constraint into an output data, and the corresponding encoder and decoder.

Abstract: In the present disclosure, a method of operating a data storage apparatus is provided. The method includes writing a data signal into a portion of a data layer in a recording medium of a data storage apparatus. The method further includes determining a data layer coupling interference value arising due to interference from the data layer provided in between a sensor head and a servo layer of the recording medium in reading servo data, the data layer coupling interference value determined based on the data signal. The method further includes writing the data layer coupling interference value onto the recording medium. A corresponding data storage apparatus is provided.

Abstract: A system for tracking a position error of a read/write head. The read/write head is configured to read data recorded to a data layer of a recording medium and read servo information recorded to a dedicated servo layer of the recording medium. To read the servo information, the read/write head is configured to read, from a first track, a first servo signal including first servo bursts of a predetermined frequency, and read, from a second track adjacent to the first track, a second servo signal including second servo bursts of the predetermined frequency. The first servo bursts are orthogonal to the second servo bursts. A position error signal determination circuit is configured to determine the position error using at least one of the first servo signal and the second servo signal.

Abstract: There is provided a method of predicting a noise component associated with a readback signal in a channel from a dedicated servo medium including a data recording layer and a dedicated servo layer. The method including: providing at least one noise prediction module for each of a plurality of types of servo patterns of the servo layer, and predicting the noise component by, for each of a plurality of segments of the readback signal of the data recording layer, using a selected one of the noise prediction modules. In particular, the selected one of the noise prediction module for a segment of the readback signal is selected based on the type of the servo pattern associated with the segment of the readback signal. There is also provided a corresponding noise predictor, a method of detecting data bits from the readback signal, and a hard disk drive system.

Abstract: A method of encoding an input data into a codeword that satisfy a k constraint includes partitioning the input data into a plurality of data blocks comprising a first data block and a plurality of remaining data blocks; performing a first analysis of the plurality of data blocks for modifying each of the plurality of remaining data blocks that satisfy a first predetermined criterion; performing a second analysis of the plurality of data blocks after the first analysis for modifying each of the plurality of data blocks that satisfy a second predetermined criterion; and converting each bit of the plurality of data blocks after the second analysis to produce the codeword in Non-Return-to-Zero (NRZ) format with the k constraint. There is also provided a method of decoding the codeword with satisfies the k constraint into an output data, and the corresponding encoder and decoder.

Abstract: There is provided a method of predicting a noise component associated with a readback signal in a channel from a dedicated servo medium including a data recording layer and a dedicated servo layer. The method including: providing at least one noise prediction module for each of a plurality of types of servo patterns of the servo layer, and predicting the noise component by, for each of a plurality of segments of the readback signal of the data recording layer, using a selected one of the noise prediction modules. In particular, the selected one of the noise prediction module for a segment of the readback signal is selected based on the type of the servo pattern associated with the segment of the readback signal. There is also provided a corresponding noise predictor, a method of detecting data bits from the readback signal, and a hard disk drive system.

Abstract: A system for tracking a position error of a read/write head. The read/write head is configured to read data recorded to a data layer of a recording medium and read servo information recorded to a dedicated servo layer of the recording medium. To read the servo information, the read/write head is configured to read, from a first track, a first servo signal including first servo bursts of a predetermined frequency, and read, from a second track adjacent to the first track, a second servo signal including second servo bursts of the predetermined frequency. The first servo bursts are orthogonal to the second servo bursts. A position error signal determination circuit is configured to determine the position error using at least one of the first servo signal and the second servo signal.

Abstract: According to various embodiments, a recording medium may be provided. The recording medium may include a dedicated servo layer configured to provide servo information. The dedicated servo layer may include a plurality of tracks. A first track may include a first servo signal. The first servo signal may include first servo bursts of a pre-determined frequency. A second track adjacent to the first track may include a second servo signal. The second servo signal may include second servo bursts of the pre-determined frequency.

Abstract: According to various embodiments, a recording medium may be provided. The recording medium may include a dedicated servo layer configured to provide servo information. The dedicated servo layer may include a plurality of tracks. A first track may include a first servo signal. The first servo signal may include first servo bursts of a pre-determined frequency. A second track adjacent to the first track may include a second servo signal. The second servo signal may include second servo bursts of the pre-determined frequency.