>

Free Space

CASTECH's Free Space Isolators could maintain the light's linear polarization, through rotating the plane of polarized light 45°in the forward direction and an additional 45°of non-reciprocal rotation in the reverse direction. CASTECH free space isolator series include 2 types :Polarization and Polarization Indepent. Meanwhile, free space isolators include fixed wavelength isolators and wavelength adjustable isolators.


  • Introduction
  • Specification
  • Course
  • Download
  • Feedback

     CASTECH's  Free Space Isolators could maintain the light's linear polarization, through rotating the plane of polarized light 45°in the forward direction and an additional 45°of non-reciprocal rotation in the reverse direction. CASTECH free space isolator series include 2 types :Polarization and Polarization Indepent. Meanwhile, free space isolators include fixed wavelength isolators and wavelength adjustable isolators. 

Features:

  ◆ High damage threshold and power handling

  ◆ Peak Isolation : Range from 30dB to 45dB

  ◆ Free space input and output

  ◆ Orthogonal isolated beams

  ◆ Isolators are available for optional λ/2 plate

  ◆ All isolators contain escape ports


Applications:

  ◆ Maintain the light's linear polarizaton

  ◆ Avoide deleterious effects of back reflectons in laser diodes

  ◆ Eliminate instability in amplified laser systems caused by ASE

  ◆ Reduce Nd and Yb oscillations from ASE created by amplifiers


Specifications:  

 


UV

VIS

NIR

IR

Center Wavelength

355nm

405-980nm

1030,1064nm

1319,2000,4500nm

Operating Wavelength Range

±10nm

±10nm

±15nm

±10nm

Peak Transmission

>93%

>90%

>92%

>90%

Peak Isolation

>35dB

>35dB

>30dB

>35dB

M2 Degradation

<10%

<10%

<10%

<10%

Clear Aperture

3,4mm or others

3,4mm or others

2,3,4,5,8,10,12 or others

3,4mm or others

Optical Power(Average)

1,5,10W or Specify

10,30,50W or Specify

10,30,50,100W or Specify

10,30,50W or Specify

Damage Threshold

3.5J/cm2@ 10ns

3.5J/cm2@ 10ns

10J/cm2@ 10ns

5J/cm2@ 10ns

Storage Temperature Range

-20-70℃

Tunable Temperature Range

10-30℃

Product specifications are subject to change without notice;

Customized (Wavelength, Dimension, Power Handling , etc) are available;

Note:All products are RoHS compliant.

 

Device

Wavelength(nm)

Aperture (mm)

Power (W)

Datasheet

Polarization Independent Isolator

980,1030,1064

1.5-5 or other

5-50

Dimension-Polarization Independent

Free Space Isolator

400-1000

2-6 or other

10-50

Dimension-VIS Free Space

1010-1080

2-12 or other

10-100

Dimension-NIR Free Space Isolator

1319, 2000, 4500

2-6 or other

10-50

Dimension-IR Free Space

Adjustable Broadband Isolator

550-750

6-10or other

30-100

Dimension-Adjustable Broadband

Dual Stage Isolator

1030,1064

2-6 or other

10-50

Dimension-Dual Stage

 

1.Introduction

The main component of the optical isolator is the Faraday rotator. The magnetic field B, applied to the Faraday rotator causes a rotation in the polarization of the light due to the Faraday effect. The angle of rotation θ is given by θ=vBL, where v is the Verdet constant of the magneto-optic material, and L is the length of the magneto-optic material. Specifically for an optical isolator, the values are chosen to give a rotation of 45°.

2.Faraday Rotator

Faraday rotator is an important optical element in an isolator. The characteristics of a Faraday rotator include a high Verdet constant, low absorption coefficient, low non-linear refractive index and high damage threshold. The two most commonly used materials for the 700–1100 nm range are terbium doped borosilicate glass and terbium gallium garnet crystal (TGG). For  infrared wavelength range, typically for the 1300-4000nm, yttrium iron garnet crystals are used (YIG).

 

Faraday rotator provides non-reciprocal rotation while maintaining linear polarization. That is, the polarization rotation due to the Faraday rotator is always in the same relative direction. So in the forward direction, the rotation is positive 45°. In the reverse direction, the rotation is −45°. This is due to the change in the relative magnetic field direction, positive one way, negative the other. This then adds to a total of 90° when the light travels in the forward direction and then the negative direction. This allows the higher isolation to be achieved.

3.Optical Isolator

Optical isolator according to its physical principles can be divided into polarization dependent isolator and polarization independent isolator.The polarization dependent isolator, or Faraday isolator, is made of three parts, an input polarizer (polarized vertically), a Faraday rotator, and an output polarizer, called an analyser (polarized at 45°).

 

Polarization dependent isolators are typically used in free space optical systems. This is because the polarization of the source is typically maintained by the system. In optical fibre systems, the polarization direction is typically dispersed in non polarization maintaining systems. Hence the angle of polarization will lead to a loss.

The polarization independent isolator is made of three parts, an input birefringent beam displacer, a Faraday rotator, a half-waveplate, and an output birefringent beam displacer.

Polarization independent isolators are typically used in fiber laser systems to maintain frequency stability, such as industrial processing areas etc.

 

  • Isolators Performance Test2018-07-14download

Dear visitors! Please submit your feedback information!

  • *Name:
  • Company:
  • *Tel:
  • *Email:
  • *Message:
  • *Code:


Copyright© CASTECH Inc. all rights reserved 闽ICP备12014619号 Copyright 2012-2017 51helpdesk.com

+-