Ring Shape Micro SmCo Permanent Magnets for Optical Isolator

Ring Shape Micro SmCo Permanent Magnets for Optical Isolator YXG-24, Custom Micro Magnetic Rings, Samarium Cobalt Rare Earth ring tiny magnets for precision optical isolator application, High Work Temp Permanent Motor Generator Rotor Magnet, Super Strong Rare Earth Cobalt, RE Cobalt, RECo and CoSm magnets China Supplier

Ring Shape Micro SmCo Permanent Magnets for Optical Isolator YXG-24 Item No. MPCO-SCR series
Customzied Specific Requirements
OEM or ODM service: Accept
Dimension: Customized size
Custom Grade: SmCo5,  Sm2Co17
Magnetization direction: Thickness, Length, Axially, Diametre, Radially, Multipolar
Surface Treatment: UNCOATED, Silver, Gold, Zinc, Ni-cu-Ni. Epoxy etc.
Tolerance: +/-0.02 – 0.05mm

Samarium Cobalt is also known as SmCo, Rare Earth Cobalt, RE Cobalt, RECo and CoSm.
Samarium Cobalt (SmCo) magnets are not as strong as the Neodymium (NdFeB) magnets (maximum energy product of between 30 and 50 MGOe) but they have three significant advantages. The SmCo magnets work over a wider temperature range, have superior temperature coefficients and have much greater corrosion resistance.

As the second strongest magnetism magnet, samarium cobalt was developed and put into operation in 1970. In 2012, the high iron concentration SmCo for generators was developed. The magnet adopted the thermal technology, so that the SmCo whose magnetic force was weaker than NdFeB became better than the heat resistant NdFeB in the environment above 100ºC. High Energy Product Rare Earth SmCo Magnetic Rings For Instruments

In order to increase the magnetic force, the research and & development staff increased the proportion of iron from 15% to 20% even 25%, and the temperature, time and pressure were adjusted in sintering to reduce the effect of oxides and other factors which block the increase of magnetism. The newly developed SmCo will completely make a great difference after alloying modification.

Polarized Type Optical-Isolator Ring SmCo Rare Earth Magnets

Advantages:
High resistance to demagnetization, High energy product, good temperature stability, high resistance of corrosion and oxidation.

Application:
Widely used in apparatus and instruments where a strong magnetic field is needed, including motors, sensors, microphones, electro-acoustics, magnetic separation, magnetic suckers and magnetic therapy etc.

An optical isolator is a device that is designed to allow the optical signal travel in the forward direction while block reflections that would travel in the backward direction. Optical isolators are critically important in many applications in optical systems. For example, a single-frequency semiconductor laser is very susceptive to external optical feedback. Even a very low level of optical reflection from an external optical circuit, on the order of − 50 dB, is sufficient to cause a significant increase in laser phase noise, intensity noise, and wavelength instability. Thus, an optical isolator is usually required at the output of each laser diode in applications that require low optical noise and stable single optical frequency. Another example is in an optical amplifier where unidirectional optical amplification is required. In this case, the bidirectional nature of optical amplification of the optical gain medium would cause self-oscillation if the external optical reflection from, for example, connectors and other optical components is strong enough. Micro Ring SmCo Magnets for Optical Isolators

A traditional optical isolator is based on a Faraday rotator sandwiched between two polarizers. In this configuration, the optical signal coming from the left side passes through the first polarizer whose optical axis is in the vertical direction, which matches the polarization orientation of the input optical signal. Then, a Faraday rotator rotates the polarization of the optical signal by 45 degree in a clockwise direction. The optical axis of the second polarizer is oriented 45 degree with respect to the first polarizer, which allows the optical signal to pass through with little attenuation. If there is a reflection from the optical circuit at the right side, the reflected optical signal has to pass through the Faraday rotator from right to left. Since the Faraday rotator is a nonreciprocal device, the polarization state of the reflected optical signal will rotate for an additional 45 degree in the same direction as the input signal, thus becoming horizontal, which is perpendicular to the optical axis of the first polarizer. In this way, the first polarizer effectively blocks the reflected optical signal and assures the unidirectional transmission of the optical isolator.

free-space optical isolators micro magnets smco ring

Samarium Cobalt (SmCo) magnets can be used over a massive temperature range. A few Neodymium magnet grades can be used at temperatures up to 220 degrees C. The SmCo magnets start to outperform the NdFeB magnets around 150-180 degrees C. Also, Samarium Cobalt magnets are ideal for very low temperature applications (SmCo can be used down to a few Kelvin above Absolute Zero) making them a first choice magnet for cryogenic applications. They can also be used in very high temperatures – up to +250 deg C or +300/+350 degrees C depending on the grade; the SmCo26 is rated to +300 degreec C) Permanent Rare Earth Sm2co17 SmCo Magnetic Ring

The magnet is a major factor in determining the size and performance of an isolator. The ultimate size of the magnet is not simply determined by magnetic field strength but is also influenced by the mechanical design. Many smco magnets are not simple one piece magnets but are complex assemblies. our modeling systems allow optimization of the many parameters that affect size, optical path length, total rotation, and field uniformity. MPCO 4,856,878 describes one such design that is used in several of the larger aperture isolators for YAG lasers . Thorlabs emphasizes that a powerful magnetic field exists around these Isolators, and thus, steel or magnetic objects should not be brought closer than 5 cm. SmCo Magnet Ring for Optical Isolator Instruments