Abstract: Disclosed are methods and configurations for monitoring reflections in heat-assisted magnetic recording (HAMR) heads that may lead to laser instability and power variation. HAMR heads direct light emitted by a laser toward a near field transducer (NFT) for the production of plasmons that assist in data recording. A certain amount of the laser light may be reflected at or near the NFT back toward the laser, and this reflected light can cause laser instabilities over time. As a screening measure during manufacturing or assembly, or as a laser health monitoring measure during drive operation, a back reflection monitor is used to detect the intensity of a portion of the reflected light. Back reflection monitoring capability may be provided by a bolometer integrated into HAMR recording head assemblies, and optionally along with optical components and electrical circuitry that provides laser light transmission monitoring capability.

Abstract: Single-transverse-mode laser diodes that include a bowtie-shaped ridge waveguide. Related apparatuses, data storage devices, computing systems, and methods.

Abstract: Provided are arrangements of optical elements that combine the features of a high power, compact laser that exhibits narrow linewidth output and that does not appreciably shift in wavelength or vary in power over a wide range of temperatures. Such arrangements include a transmission filter and a Bragg reflector that select out the wavelength for which the output power of a reflective semiconductor optical amplifier (RSOA) is least affected by changes in temperature over a temperature range of interest. Such arrangements may also utilize temperature-insensitive materials.

Abstract: A hard disk drive (HDD) includes a heat-assisted magnetic recording (HAMR) head. The HAMR head includes one or more features comprising a laser device that is a heterogeneous integrated epitaxial grown GaAS laser. The laser device couples directly with a waveguide that transfers the electromagnetic radiation generated by the laser device to a near field transducer. The device includes an N-doped layer for coupling the output of the GaAs active layer to the waveguide.

Abstract: A laser-based molecular sequencing system includes a two-dimensional photonic crystal surface emitting laser (PCSEL) array including a plurality of PCSEL devices located in a first layer, each PCSEL device oriented in a direction perpendicular to the first layer. The system also includes a controller configured to modulate a bias on at least one PCSEL device of the plurality of PCSEL devices, the modulation configured to selectively operate each PCSEL device as an emitter or detector at a point in time based on the bias.

Abstract: A laser-based computing system includes a two-dimensional photonic crystal surface emitting laser (PCSEL) array including a plurality of PCSEL emitters located in a first layer, each emitter oriented in a direction perpendicular to a plane formed by the first layer, where the plurality of PCSEL emitters form a preset pattern within the first layer, and a controller operatively connected to the plurality of PCSEL emitters, the controller configured to modulate phase and/or amplitude of a beam emitted by a PCSEL emitter of the plurality of PCSEL emitters.

Abstract: A recording head comprises a write pole extending to an air-bearing surface. A near-field transducer is positioned proximate a first side of the write pole in a down-track direction. A heatsink structure is proximate the near-field transducer and positioned between the near-field transducer and the write pole. The heatsink structure extends beyond the near-field transducer in a cross-track direction and extends in a direction normal to the air-bearing surface.

Abstract: An external cavity laser of a recording head includes a channel waveguide that delivers light towards a media-facing surface of the recording head. The laser includes an externally mounted part with an active region having a longitudinal axis corresponding to a light propagation direction of the channel waveguide. The externally mounted part has a reflective back facet and anti-reflective front facet. The laser includes a near-field transducer at an end of the channel waveguide proximate the media facing surface. The reflective back facet and the near-field transducer define a resonator of the external cavity laser.

Abstract: A Surface-Enhanced Raman Spectroscopy (SERS) device to perform accurate label-free long-read DNA sequencing. A Raman sensor has a hot spot defined by plasmonic nanostructures and excited by at least one laser. An immobilized DNA polymerase can be used to pull a DNA template strand to be sequenced through the hot spot.

Abstract: A mechanism is provided in a data processing system having a processor and a memory. The memory comprises instructions which are executed by the processor to cause the processor to implement a training system for finding an optimal surface for hierarchical classification task on an ontology. The training system receives a training data set and a hierarchical classification ontology data structure. The training system generates a neural network architecture based on the training data set and the hierarchical classification ontology data structure. The neural network architecture comprises an indicative layer, a parent tier (PT) output and a lower leaf tier (LLT) output. The training system trains the neural network architecture to classify the training data set to leaf nodes at the LLT output and parent nodes at the PT output. The indicative layer in the neural network architecture determines a surface that passes through each path from a root to a leaf node in the hierarchical ontology data structure.

Abstract: A recording head comprises a write pole extending to an air-bearing surface. A near-field transducer is positioned proximate a first side of the write pole in a down-track direction. A heatsink structure is proximate the near-field transducer and positioned between the near-field transducer and the write pole. The heatsink structure extends beyond the near-field transducer in a cross-track direction and extends in a direction normal to the air-bearing surface.

Abstract: An apparatus comprises a slider configured for heat-assisted magnetic recording comprising an air bearing surface (ABS). The slider comprises a write pole at or near the ABS, and a near-field transducer (NFT) at or near the ABS and proximate the write pole. A main waveguide is configured to receive light from a laser source and communicate the light to the NFT. An optical power sensor comprises a tap waveguide optically coupled to the main waveguide and comprising a first end and an opposing second end. The optical power sensor also comprises a bolometer optically coupled to the tap waveguide and configured to receive a portion of the light extracted from the main waveguide by the tap waveguide.

Abstract: A recording head comprises a write pole extending to an air-bearing surface. A near-field transducer is positioned proximate a first side of the write pole in a down-track direction. A heatsink structure is proximate the near-field transducer and positioned between the near-field transducer and the write pole. The heatsink structure extends beyond the near-field transducer in a cross-track direction and extends in a direction normal to the air-bearing surface.

Abstract: A recording head includes an external cavity laser with an externally mounted part having an active region. The external cavity laser also includes a channel waveguide that delivers light towards a media-facing surface. A near-field transducer functions as a reflector, either alone or in combination with a Bragg grating in the channel waveguide. A reflective back facet of the externally mounted part and the reflector define a resonator of the external cavity laser.

Abstract: An integrated on-chip system and methods for real-time molecular sequencing. The system has a semiconductor chip and a laser. The semiconductor chip has integrated therein a main waveguide, a plurality of branch waveguides optically connected to the main waveguide, a plurality of nanochannels each having a fluid inlet and a fluid outlet, a plurality of molecule traps, a molecule trap at an intersection of a branch waveguide and a nanochannel, and a plurality of photodetectors operably connected to the plurality of molecule traps, one photodetector for a molecule trap, the photodetector to detect a spectral signature from a molecule in the molecule trap. The laser is optically connected to the main waveguide.

Abstract: An apparatus comprises a slider configured for heat-assisted magnetic recording comprising an air bearing surface (ABS). The slider comprises a write pole at or near the ABS, and a near-field transducer (NFT) at or near the ABS and proximate the write pole. A main waveguide is configured to receive light from a laser source and communicate the light to the NFT. An optical power sensor comprises a tap waveguide optically coupled to the main waveguide and comprising a first end and an opposing second end. The optical power sensor also comprises a bolometer optically coupled to the tap waveguide and configured to receive a portion of the light extracted from the main waveguide by the tap waveguide.

Abstract: A recording head comprises a write pole extending to an air-bearing surface. A near-field transducer is positioned proximate a first side of the write pole in a down-track direction. A heatsink structure is proximate the near-field transducer and positioned between the near-field transducer and the write pole. The heatsink structure extends beyond the near-field transducer in a cross-track direction and extends in a direction normal to the air-bearing surface.

Abstract: An apparatus comprises a slider configured for heat-assisted magnetic recording comprising an air bearing surface (ABS). The slider comprises a write pole at or near the ABS, and a near-field transducer (NFT) at or near the ABS and proximate the write pole. A main waveguide is configured to receive light from a laser source and communicate the light to the NFT. An optical power sensor comprises a tap waveguide optically coupled to the main waveguide and comprising a first end and an opposing second end. The optical power sensor also comprises a bolometer optically coupled to the tap waveguide and configured to receive a portion of the light extracted from the main waveguide by the tap waveguide.

Abstract: A Surface-Enhanced Raman Spectroscopy (SERS) device to perform accurate label-free long-read DNA sequencing. A Raman sensor has a hot spot defined by plasmonic nanostructures and excited by at least one laser. An immobilized DNA polymerase can be used to pull a DNA template strand to be sequenced through the hot spot.

Abstract: A recording head comprises a write pole extending to an air-bearing surface. A near-field transducer is positioned proximate a first side of the write pole in a down-track direction. A heatsink structure is proximate the near-field transducer and positioned between the near-field transducer and the write pole. The heatsink structure extends beyond the near-field transducer in a cross-track direction and extends in a direction normal to the air-bearing surface.