One widely used photodetector is the pin photodetector (pin-PD), which has a depleted absorption layer of intrinsic semiconductor (i-layer) between positively and negatively doped electrode layers (p- and n-type semiconductor layers). In a pin-PD, two types of charge carriers—both negative electrons and positive holes—are photogenerated and contribute to the external induced current. Because holes have a much lower velocity than electrons (1/10 the speed), the device’s response speed is dominated by hole transport. Therefore, we developed the UTC-PD, which can achieve ultrahigh-speed operation, by removing this limiting factor for the pin-PD. As illustrated in Fig. 1, carriers are generated in the p-type absorption layers and only electrons are injected into the depleted carrier collection layer, whose thickness is designed independently of the absorption layer. Since the holes are majority carriers in the p-type absorption layer, their transport is the collective motion with a high response time determined by the dielectric relaxation time. Eventually, only electrons behave as active carriers in the UTC-PD; thus, UTC-PDs can achieve ultrahigh-speed and high-current operation without the space-charge-effect induced by hole accumulation.

NEON has built a reputation on custom solutions. Whether you need a small modification to an existing system or a completely novel design built from the ground up to meet your technical specifications, Neon\’s engineering and optical delay line design teams are ready to help.

Radio altimeter test set is portable, inexpensive An inexpensive universal test set for 4.3-GHz FMCW- and pulse-radio altimeters, the ALT-8000 RF-based portable radio altimeter test set is said to be the first of its kind. Designed for Flightline testing of aircraft and UAVs, it has a 12-in. color touchscreen to ease operation.

The radio altimeter test set system can be coupled to the altimeter directly through the latter’s Tx/Rx ports or by using the supplied antenna couplers, which accommodate most aircraft. RF looped tests verify Tx frequency, power, and sweep rate, while the RF-level control permits testing UUT sensitivity. The unit can simulate altitude from –100 to 50,000 ft with ±1.5-ft accuracy, be programmed with multileg climb / descend profiles, and be connected to up to two other test sets for coordinated two- or three-channel simulation.

50G Ethernet QSFP28 Transceivers are designed for 50G Ethernet application using fixed 103.25 Gbps data rate, comprehending 50G SR4, BiDi SR4, LR4, ER4 Lite, ZR4 which are defined by IEEE 802.3ba/802.3bm, 2km PSM4 which is defined by 50G PAM4 BIDI and CWDM4/CLR4 modules which are defined by 50G QSFP28 SM. Additionally, there are 2 special modules: 50G QSFP28 SM Low Power module which is useful in modern data center environments and can help to save power and lower heat dissipation and there is 50G QSFP28 LR4 Long Haul (20km) module which is extended reach version of 50G LR4.

The acronym DFB stands for distributed feedback laser. Their key features relative to other semiconductor lasers are their single longitudinal mode (single frequency) emission profile, their high stability and their tunability. These single frequency laser diodes are used in applications such as fiber optic telecommunications, spectroscopy, metrology and atomic physics. This sub-category of semiconductor lasers employs Bragg diffraction gratings in the active gain region of the semiconductor to form a waveguide. These diffraction gratings are designed to deliver periodic changes in the refractive index which cause a reflection back into the cavity of the laser. Unlike Fabry-Perot laser diodes, which utilize mirrors at both ends of the laser cavity, the reflection of the laser light in a DFB Laser Diode is along the entire cavity. DFB semiconductor materials include indium-phosphide and gallium-indium-arsenide-antimony.

Single Frequency Laser Diodes have a wavelength-selective grating integrated in the laser chip. Thus they operate on a single resonator mode emitting quasi-monochromatic radiation with a very small linewidth and low phase noise. The lasers can have very low-intensity noise because of the lack of mode partition noise. Due to the Gaussian mode the output is diffraction-limited.

QSFP28 optical transceivers, also known as quad small form factor 28 pluggable, are compact, hot-pluggable modules used for data communications applications. The QSFP28 format allows for 2×25 Gbit/s transmission and is capable of handling 100G traffic. QSFP28 can do a 2x25G breakout connection depending on the transceiver used. The NEON optics range of QSFP28 optical transceivers is comprehensive and meets the standards for usage for Ethernet, Fibre Channel Protocol and SONET/SDH set forth in MSA (multi-source agreement). All QSFP28 optical transceivers are supplied to us by the same manufacturing facilities used by the big name vendors and then fully tested in our NEON optics instrument and a selection of the equipment platforms at our telecoms test lab before dispatch. You will find a snapshot of the QSFP28 optical transceivers that NEON optics can offer at a fraction of the cost of OEM supply.

Marine watertight doors are available in aluminum, steel or a combination of these metals meeting IMO, SOLAS requirements. It can be opened and closed quickly and lightly. It is used for bulkheads with water tightness requirements. It can prevent the ingress of water from one compartment to another during flooding or accidents and therefore act as a safety barrier.

It limits the spread of water inside the vessel. These doors are used onboard in many ships such as in the fore and aft passageways underdeck and in engine room bulkheads leading to shaft tunnels in container vessels, large passenger ships, offshore vessels, oil exploration vessels.

They are used in areas where the chances of flooding are high. Areas such as engine room compartments and shaft tunnel and some of such places.

Therefore it is important that crew members are familiar with the system as well as the location of different powered watertight doors aboard the ship.

Watertight as defined in SOLAS is: capable of preventing the passage of water in any direction under the head of water likely to occur in intact and damaged conditions.

Weathertight is defined as that in any sea conditions water will not penetrate the ship.

To make it simpler, a watertight door can prevent the passage of water in both directions when subjected to ahead of water i.e it can withstand water pressure from both sides. They are designed to withstand continuous submersion and are therefore located below the waterline like shaft tunnels, ballast tanks, bow thruster compartments, etc. all openings below the waterline have to be watertight.

Watertight Doors Drill on Ships

1. Drills for the operation of watertight doors shall take place every week. Also, the doors should be checked before leaving the port.

2. All watertight doors, both hinged and power operated should be operated daily during the rounds.

3. The door should be able to operate from both local and remote places. i.e. bridge and ship control center.

4. If the door is operated from a remote location, there should be an audio and visual alarm during the closing

5. There should be an indication of both open and close on the remote place of operation.

Maintenance of Watertight Doors

The ship’s planned maintenance system must be followed for carrying out routine inspection and maintenance on watertight doors which should include the correct functioning of the whole system and specifically:

Warning devices and alarms

The electric/hydraulic mechanism

Valves

Fluid level indicators

Seals

Lights

All marine watertight doors provided by YSmarines have the certificate of GL- DNV, CCS, BV, ABS, LR, KR, RS, etc with customized sizes and colors, superior quality. For more detailed information, please visit the official site of ysmarines.com.

An active web guiding system is composed of a sensor, an actuator, and a controller. The web guide actuators are used for the fast response to the changes in the web edge position.

How dodes the web guide actuator work

When the output of the sensor goes to a controller which outputs a movement command to the actuator, the actuator which moves the guide mechanism may be a stepper motor and ballscrew for smaller assemblies.

Specifications of web guide actuator

Power supply voltage: DC 24V

Maximum speed: 30mm/s

Maximum stroke: 150mm

Maximum thrust: 200KG.F

Back-off error: less than 0.001mm

Push load: 2000KG

Advantages of web guide actuator

1. It adopts Japan’s Sanyo electric motor as the actuator, without carbon brush

2. Fully reliable and long service life, truly realize long-term maintenance-free during use

3. It has the characteristics of energy-saving and environmental-friendly

4. Adopting Taiwan precision ball screw with the smallest gap

5. Clearance and durability, so that the actuator has no backlash error.

6. Choosing from75-300mm stroke, 0.5T-10T thrust weight

7. Installation method has direct connection type and L type

Arise provides SE-150S/150/300/300S/75S type servo web guide actuator with advanced technology, superior quality and the most competitive prices.