Polarization Maintaining Optical Circulator (High Extinction Ratio)

The polarization maintaining optical circulator (high extinction ratio) is a passive component based on the Faraday effect, transmitting light signals from one port to the next sequential port with low loss, but at the same time blocking any light transmission to the previous port. By using polarization maintaining fiber (PMF), it is able to maintain the same state of polarization (SOP) of the light signals. The 3-port polarization maintaining optical circulator (high extinction ratio) can work on both slow-axis and fast-axis linear polarizations, or just transmit one principal polarization state in only one direction and block the orthogonal state in both directions. Related Products ↓

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Basics of Polarization Maintaining Optical Circulator (High Extinction Ratio)

The polarization maintaining optical circulator is based on the use, precise positioning and alignment of miniaturized traditional optical components such as polarizing beam splitter, reflector prism, bi-refringent blocks, Faraday rotator, and retardation plate, etc.

The operation of high extinction ratio polarization maintaining optical circulator is based on two main principles: polarization splitting and recombining together with nonreciprocal polarization rotation, and asymmetric field conversion with nonreciprocal phase shift.

There are different designs for polarization maintaining optical circulator (high extinction ratio), and all of them involve the non-reciprocal property of Faraday effect. The Faraday effect is a magneto-optic effect, in which the polarization of light is rotated in an optical medium with a magnetic field applied along the light propagation direction.

High Extinction Ratio Polarization Maintaining (PM) Optical Circulator

Three-port devices are the most common; however, four-port devices are available with light entering the third port leaving through the fourth. Although it is also possible to produce a circulator with a larger number of ports, the device complexity increases with increasing number of ports and therefore in practice only three- or four-port circulators have proved useful for optical interconnection.

Due to the compact design, low insertion loss, high isolation, and high reliability, Lfiber’s polarization maintaining optical circulator (high extinction ratio) is a good choice for many industrial applications including fiber optical instruments, fiber sensors, and fiber laser.

Polarization Maintaining Optical Circulator (High Extinction Ratio)

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FEATURES OF POLARIZATION MAINTAINING (PM) OPTICAL CIRCULATOR

Low Insertion Loss
High Isolation & Extinction Ratio
High Reliability & Stability

APPLICATIONS OF POLARIZATION MAINTAINING (PM) OPTICAL CIRCULATOR

EDFA& Raman Amplifier
Fiber Sensor
Fiber Instrument

Polarization Maintaining Optical Circulator (High Extinction Ratio, 1064nm 1310nm 1550nm)
Type	Type A		Type B
Port Type	3 Port	4 Port	3 Port	4 Port	3 Port	4 Port
Center Wavelength (nm)	1310 or 1550		1310 or 1550		1064
Operating Wavelength Range (nm)	±30		±20		±5
Typ. Insertion Loss at 23 ℃ (dB)	0.7	1.1	0.6	1.0	1.8	2.2
Max. Insertion Loss at 23 ℃ (dB)	0.9	1.3	0.8	1.2	2.1	2.5
Typ. Peak Isolation 23 ℃ (dB)	46		30		30
Min. Isolation at 23 ℃ (dB)	40		20		25
Min. Extinction Ratio at 23 ℃ (dB)	22 (default), 28		20 (default), 28		20 (default), 28
Min. Cross Talk (dB)	50
Min. Return Loss (dB)	50
Max. Optical Power (CW) (mW)	300
Max. Tensile Load (N)	5
Operating Temperature (°C)	-5~+70
Storage Temperature (°C)	-40~+85

Notes:

High extinction ratio greater than 28dB is available only for the 3-port polarization maintaining optical circulator.
Unless otherwise specified, the slow axis of the fiber is aligned with the key of the PM fiber connector.
Slow axis working and fast axis blocked as standard, while operating on both the slow and fast axis available on request.
Working on both the slow and fast axis is available only for 3-port polarization maintaining optical circulator
For the device with connector, IL is 0.3dB higher, RL is 5dB lower, and ER will be 2dB lower.
This polarization maintaining optical circulator is customizable and the above specifications are subject to change without notice.
For product customization or special requirements, please contact Lfiber’s sales department for availability.

Package Dimensions & Routing Characteristics

Routing (Type A & Type B): 1 → 2, 2 → 3

Polarization Maintaining (PM) Optical Circulator High Extinction Ratio

Routing (Type A): 1 → 2, 2 → 3, 3 → 4

(Type B): 1 → 2, 2 → 3, 3 → 4, 4 → 1

Ordering Information of Polarization Maintaining Optical Circulator (High Extinction Ratio)
Center Wavelength	Port Type	Type	Axis Alignment	Fiber Type	Package Dimension	Pigtail Type	Fiber Length	Connector
1064nm	3-Port	Type A	Slow axis working, fast axis blocked	PM1550	Φ5.5×35mm	250μm bare fiber	0.8m	None
1310nm	4-Port	Type B	Fast axis working and slow axis blocked	PM1310	Custom …	900μm loose tube	1m	FC/UPC
1550nm			Both axis working (only for 3-port)	PM980			Custom …	FC/APC
								SC/UPC
								SC/APC
								LC/UPC
								LC/APC

About Axis Alignment of the High-ER Polarization Maintaining (PM) Fiber Optical Circulator

“Slow axis working and fast axis blocked” means that light on just the slow axis is transmitted from port 1 to port 2, from port 2 to port 3, and also from port 3 to port 4; Fast axis light is blocked in the forward direction. In the backward direction (from port 2 to port 1, from port 3 to port 2, and from port 4 to port 3), both the slow and fast axis light are blocked
“Both axis working” means that both the slow and fast axis light are transmitted in the forward direction, both the slow and fast axis light are blocked in the backward direction.