Polarization Independent Reflective Modulator for High-Temperature Operation

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Solution Overview

Problem

Current optical modulators in carrier distribution schemes are temperature-sensitive and limited by low speed, making them unsuitable for high-temperature, high-speed applications, as they fail to properly modulate uplink signals in uncooled environments exceeding 85°C or requiring high-speed operation.

Innovation Solution

The development of a polarization independent reflective modulator (PIRM) that splits incoming optical carriers into perpendicular polarization components, rotates one component to match the other, allowing simultaneous modulation by a temperature-insensitive modulator, thus eliminating polarization dependence and enabling operation in high-temperature environments without the need for cooling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional modulators are used in carrier distribution schemes, then the system can operate with simple architecture, but the modulators are temperature-sensitive and limited to low-speed operation to avoid overheating, making them unsuitable for high-temperature environments exceeding 85°C

Engineering Contradiction:
Improvesystem architecture simplicityVSAvoidmodulator performance in high-temperature environments
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The optical carrier signal is divided into two orthogonal polarization components (TE and TM modes) that travel through separate waveguide paths. Each polarization component is independently modulated by dedicated modulators, allowing the system to handle high-temperature operation by distributing thermal load and enabling polarization-independent modulation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces a polarization dimension by splitting the optical signal into orthogonal polarization states. This dimensional approach allows the system to eliminate polarization dependence and achieve temperature-insensitive operation by utilizing both TE and TM modes simultaneously through separate modulation paths.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If conventional modulators operate at high speeds, then the system achieves high data transmission rates, but the modulators overheat and fail to properly modulate uplink signals

Engineering Contradiction:
Improvemodulation speedVSAvoidmodulator operating temperature
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

The high-speed modulation task is segmented across multiple parallel modulator channels handling different polarization components. This distribution allows each modulator to operate at high speed without excessive heat accumulation, as the thermal load is divided among multiple devices operating in parallel.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple polarization components (TE and TM modes) are combined at the output to form a single modulated optical signal. This merging approach allows the system to achieve high-speed modulation by combining the output of multiple modulators, each operating at manageable temperature levels.

Inventive Principle:
Principle #5Merging (Combining)

3Use of energy by stationary object

If the remote device is uncooled to reduce power consumption and cost, then the device can operate in high-temperature environments, but conventional modulators cannot properly modulate signals at temperatures exceeding 85°C

Engineering Contradiction:
Improvecooling power consumptionVSAvoidmodulator functionality in uncooled conditions
Core Design Contradiction:
Use of energy by stationary objectVSReliability

Solution Approach 1:

The invention changes the operational parameters by utilizing orthogonal polarization modes (TE and TM) that can be independently modulated. This parameter change allows the modulator system to maintain proper signal modulation capability across a wider temperature range, including uncooled high-temperature environments above 85°C.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The modulator system is designed to handle multiple polarization components universally, making it adaptable to various temperature conditions without requiring active cooling. The polarization-independent design allows the same device to function reliably whether cooled or uncooled, eliminating the need for temperature-dependent operation.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The PIRM allows for reliable high-speed modulation of uplink signals in high-temperature conditions, reducing power consumption and eliminating the need for thermoelectric cooling, while supporting wavelength division multiplexing and enabling cost-effective production of remote radio units.

Implementation Method 1

a polarization beam splitter (PBS) configured to split the optical carrier into a first polarized component and a second polarized component

Methodology Applied
Scientific EffectPolarization beam splitting: Polarisation

Implementation Method 2

a polarization rotator configured to rotate a polarization state of the first polarized component by 90 degrees

Methodology Applied
Scientific EffectFaraday rotation: Faraday Effect

Data Source

PatentEP3289407B1Polarization independent reflective modulator
Publication Date: 2019.06.26 HUAWEI TECH CO LTD
  • EP3289407B1 patent drawingFigure 1
  • EP3289407B1 patent drawingFigure 2
  • EP3289407B1 patent drawingFigure 3

AI summary

An apparatus and a method are provided. The apparatus (100) comprises an optical input (147) configured to receive an optical carrier (141), an polarization beam splitter (155) configured to forward a first polarized component of the optical carrier (141) along a first light path (156), and forward a second polarized component of the optical carrier (141) along a second light path (158), and an optical modulator (159). The first polarized component comprises a first polarization (TE) that is perpendicular to a second polarization (TM) of the second polarized component upon exiting the optical splitter (155). The optical modulator (159) is coupled to the first light path (156) and the second light path (158), and is configured to modulate the first polarized component of the optical carrier and the second polarized component of the optical carrier.