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RLU - compact laser unit with fibre optic delivery

Renishaw laser units combine the ultimate performance from displacement interferometers with the ease of installation associated with traditional tape and glass scale encoders.

RLE System

The RLE system is a unique, advanced homodyne laser interferometer system specifically designed for position feedback applications. Each RLE system consists of an RLU laser unit and one or two RLD10 detector heads, the model of which is dependent upon the requirements of the specific application.

Available in single or dual axis configurations, the RLU laser unit contains a HeNe (Helium / Neon) laser source, stabilisation electronics, fibre optic launch and axis position feedback electronics.

We consistently exceed the specifications of customers with Renishaw's encoders. We try to offer a best-in-class experience to our customers and attribute part of our continuing success to the technology advancements that companies like Renishaw offer.

Aerotech (USA)

Renishaw currently offer two versions of laser unit which differ in performance:

RLU10 laser unit

RLU10 offers a laser frequency stability of ±50 ppb over any one hour time period, which offers performance levels suitable for the majority of 'in air' applications.

Features and benefits

Combining the RLU10 with Renishaw detector heads (RLDs) suitable for the required application offers the following features and benefits:

  • Simple system architecture - utilising Renishaw's unique fibre optic delivery system
  • Rapid alignment - RLD detector heads allow for laser beams to be mounted directly to the measurement axis
  • Compact and easy to set up - with minimal system footprint and installation time

RLU10 overview

Fibre lengths3 m or 6 m*
Number of axesSingle or dual*
Laser sourceClass 2 HeNe
OutputsAnalogue / digital quadrature
VelocitiesUp to 2 m/s**

* Configured from the factory
** Version / resolution dependent

RLU10 performance

Laser frequency stability (1 minute)

‹±10 ppb

Laser frequency stability (1 hour)

‹±50 ppb

Laser frequency stability (8 hours)

‹±50 ppb

Vacuum wavelength stability (over 3 years)

±0.1 ppm

XY stage application

Looking for a suitable laser encoder for an XY stage application within an 'in air' environment? The RLE10-DX-XG is a popular choice for this type of application, utilising our RLU10 laser unit combined with two RLD10-A3-P9 (plane mirror interferometer 90°) heads.

RLU20 laser unit

RLU20 offers a laser frequency stability of ±2 ppb over any one hour time period, which provides ultimate measurement performance for the majority of vacuum applications.

Features and benefits

Combining the RLU20 with Renishaw detector heads (RLDs) suitable for the required application offers the following features and benefits:

  • Simple system architecture - utilising Renishaw's unique fibre optic delivery system
  • Rapid alignment - RLD detector heads allow for laser beams to be mounted directly to the measurement axis
  • Compact and easy to set up - minimal system footprint and installation time

RLU20 overview

Fibre lengths3 m only*
Number of axesSingle or dual*
Laser sourceClass 2 HeNe
OutputsAnalogue / digital
VelocitiesUp to 2 m/s**

* Configured from the factory
** Version / resolution dependent

RLU20 performance

Laser frequency stability (1 minute)‹±1 ppb
Laser frequency stability (1 hour)‹±2 ppb
Laser frequency stability (8 hours)‹±20 ppb
Vacuum wavelength stability (over 3 years)±0.1 ppm

Differential measurement application

Looking for a suitable laser encoder for a differential measurement application within a vacuum environment? The RLE20-DX-XP system is a popular choice for this type of application, utilising our RLU20 laser unit with two RLD10-X3-DI (differential interferometer) heads.

Configuring an RLE system

In order to operate as a displacement interferometer, Renishaw's laser unit needs to be joined with a suitable head for the application. The following options should be considered when defining your RLE system:

  • Laser source (RLU10 or RLU20)
  • Length of the fibre 3 m or 6 m (RLE10 only)
  • Calibration certificate (option at added cost)
  • Plane mirror or retroreflector target optics
  • RLD detector head type for each axis
  • Beam output orientation for each axis (not applicable for the differential interferometer head)

To determine the RLE laser encoder system part number required for your individual application, simply enter the requirements of your application into the part number generator. It will automatically calculate the necessary system part number which can then be used to request a quotation or place an order.

Product information

Other items of interest

RLD10 0° launch detector head
RLD10 plane mirror interferometer
The RLD10-PMI (Plane Mirror Interferometer) is a double pass interferometer system configured for applications where plane mirror is required (for example XY stage applications).
RLD10 90° launch detector head
RLD10 retroreflector interferometer
The RLD10-RRI (retroreflector interferometer) is a single pass interferometer configured for applications where a retroreflector is required (for example longer range or high speed applications).
RLD10 DI
RLD10 differential interferometer
The RLD10 DI (differential interferometer) is a double pass interferometer system design to provide a differential measurement. Ideally suited for vacuum chamber applications.
RLD10 0° launch detector head
RLD10 no internal interferometer
The RLD10-XX (no internal interferometer) detector head is designed with no internal interferometer optics. This allows for the head to be used in a sequence with specialist optics to achieve linear, angular and straightness measurements.