Abstract: Provided are a method and device for fault estimation of a measurement and control device for a rotary steerable drilling system. The method for fault estimation includes: S1, establishing a state model of the measurement and control device for the rotary steerable drilling system; S2, establishing a fault-free model filter and a fault model filter, and initializing the fault-free model filter and the fault model filter; S3, detecting whether the measurement and control device for the rotary steerable drilling system has a fault; and S4, reinitializing the fault model filter under the condition that a detection result is fault-free; reinitializing the fault-free model filter under the condition that the detection result is faulty; and estimating, by the fault model filter, the fault in real time, and obtaining, by the fault model filter, the estimation value {circumflex over (x)}wf.

Abstract: A fiber attachment structure may comprise a monolithic platform structure having a first trench and a second trench to segment the monolithic platform structure into a chip mount area, a first island, and a second island. A laser chip may be mounted directly on the chip mount area and an optical fiber may be mounted on the first island by a first adhesive joint and on the second island by a second adhesive joint. For example, in some implementations, the first adhesive joint may include a first quantity of adhesive material attaching the optical fiber to the first island at a position at which a tip of the optical fiber is aligned with an output facet of the laser chip, and the second adhesive joint may include a second quantity of the adhesive material to mechanically secure the optical fiber to the second island.

Abstract: A fiber attachment structure may comprise a monolithic platform structure having a first trench and a second trench to segment the monolithic platform structure into a chip mount area, a first island, and a second island. A laser chip may be mounted directly on the chip mount area and an optical fiber may be mounted on the first island by a first adhesive joint and on the second island by a second adhesive joint. For example, in some implementations, the first adhesive joint may include a first quantity of adhesive material attaching the optical fiber to the first island at a position at which a tip of the optical fiber is aligned with an output facet of the laser chip, and the second adhesive joint may include a second quantity of the adhesive material to mechanically secure the optical fiber to the second island.

Abstract: A pump laser package may include an input fiber to send signal light on a first optical path. A first lens may be arranged on the first optical path. The pump laser package may include a source to send pump light on a second optical path. A second lens and a negative lens may be arranged on the second optical path. The first lens and the negative lens may be arranged to create a virtual image associated with the pump light. The pump laser package may include an output fiber on a third optical path. The first lens may be arranged on the third optical path. The pump laser package may include a combiner to receive the signal light on the first optical path, receive the pump light on the second optical path, and send the signal light and the pump light on the third optical path.

Abstract: A pump laser package may include an input fiber to send signal light on a first optical path. A first lens may be arranged on the first optical path. The pump laser package may include a source to send pump light on a second optical path. A second lens and a negative lens may be arranged on the second optical path. The first lens and the negative lens may be arranged to create a virtual image associated with the pump light. The pump laser package may include an output fiber on a third optical path. The first lens may be arranged on the third optical path. The pump laser package may include a combiner to receive the signal light on the first optical path, receive the pump light on the second optical path, and send the signal light and the pump light on the third optical path.

Abstract: A novel head stack assembly (HSA) is disclosed and claimed. The HSA includes first and second actuator arms. A first head gimbal assembly is attached to the first actuator arm. The first head gimbal assembly includes a read head. A dummy mass is attached to the second actuator arm. The dummy mass includes a mounting plate portion defining a mounting plate width, a neck portion defining a neck width and a neck length, and a distal mass portion defining a distal mass width and a distal mass length. The neck width is less than the mounting plate width and the neck width is less than the distal mass width.