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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.

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 Helium Neon (HeNe) laser source, stabilisation electronics, fibre optic launch and axis position feedback electronics.

The RLD detector head is the core of the optical measuring system, containing interferometer optics, a unique, multichannel fringe detection system and beam steering mechanisms. Renishaw offer three interferometer configurations (RLD10 plane mirror, RLD10 retroreflector and RLD10 differential) plus a RLD10 no internal interferometer.

Features and benefits

Combine the RLU10 or RLU20 laser with RLD detector heads suitable for the application to gain::

  • 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

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)

RLU10 laser

The RLU10 laser 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.

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 aser 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 combined with two RLD10-A3-P9, RLD10 plane mirror interferometers.

RLU20 laser

The RLU20 laser 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.

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 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 with two RLD10-X3-DI differential interferometers.

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

Use our RLE part number generator to identify the system suitable for your application which can be used to request a quotation or place an order.

Discover our range of interferometric laser encoders providing the ultimate accuracy in linear position feedback.

FAQs

What is the highest resolution that can be achieved with an RLE system?

When combining the RLE system with the RPI30 parallel interface it is possible to achieve a resolution of 38.6 pico-metres at 1 m/s.

Is it possible to supply a calibration certificate for my RLE system?

Yes, these can be specified when ordering a new system. Please note that there is an additional charge for this service.

Should I use a plane mirror or retroreflector target within my applications?

The choice of target does depend on the application type as each have their own advantages. A plane mirror is more suitable for XY stage applications. Retroreflectors are more tolerable to angular rotation than plane mirrors and are typically used on linear axes.

What mirrors does Renishaw recommend for use with the RLE system?

Renishaw offers a range of mirrors and optics suitable for your application. Our plane mirrors and mirror mounts data sheet contains information to source custom mirrors.

Additional resources

 

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