90° Optical Hybrid
To be used for optical coherent detection, including QPSK receiver, Optoplex’s six-port 90° Optical Hybrid mixes the incoming signal with the reference signal to generate four quadratural states in the complex-field space. The optical hybrid then delivers the four light signals to two pairs of balanced detectors. See the block diagram below for the application of 90° Optical Hybrid in a coherent receiver.
Optoplex’s free-space micro-optics-based, passive 90º Optical Hybrid is suitable for coherent signal demodulation, BPSK or QPSK demodulation. The patent-pending, broadband device accepts the two optical signals (S & L) and generates four output signals: S+L, S-L, S+jL, S-jL, as shown below. When these signals are detected by two balanced receivers, both the amplitude and the relative phase information between the input signals can be extracted via differential detection and digital signal processing. Moreover, in a coherent system, the preservation of the optical phase can be used to cost-effectively compensate optical transmission impairments in the electrical domain.
Key Features and Benefits
• Purely passive (no need for external electric power)
• Compact size
• Based on free-space bulk-optics design
• Polarization diversified version also available
Applications
• Key component for the optical coherent detection
• QPSK demodulation
Parameter
Unit
Specification
Wavelength Range (C- or L-Band)
nm
1527 ~ 1567
Phase Difference1 (between M1, M2 and M3, M4)
deg
90 ± 5
Insertion Loss1
(without connector)
S→Mi
dB
< 8.5
L→Mi
dB
< 8.5
Insertion Loss Difference1
between S→M1 and S→M2
dB
< 1.2
between S→M3 and S→M4
dB
< 1.2
between L→M1 and L→M2
dB
< 1.2
between L→M3 and L→M4
dB
< 1.2
Optical Return Loss
dB
> 27
Optical Path Difference
(skew, between M1 and M2 and between M3 and M4)
ps
<1
Optical Path Difference
(skew, between any other two outputs)
mm
<2 in fiber length
Operating Temperature
oC
15 ~ 35
Storage Temperature
oC
−40 ~ 85
Dimension (L×W×H)2
mm
30×30×15.5
Fiber Type
-
SMF-28 with 900 μm loose tube
Connector Type
-
TBD
Notes:
1. Over the stated spectral and operating temperature ranges and all polarization states.Subject to change, not including collimator sleeves extending from the two adjacent sides by 21 mm.
商品属性 [波长] 1527 ~ 1567nm [光纤类型] SMF-28 with 900 μm loose tube