Compact laser unit with fibre optic delivery (RLU SERIES)
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. The system provides the user with sub nanometer
resolution capability at velocities of up to 2 m/sec (80 inch/sec) for axis
lengths of up to 4 m (160 inches). To maximize application flexibility, all RLE
system components are compatible, enabling the best solution for individual
applications to be selected at component level.
The range of user selectable components within the RLE system includes
two laser units and six RLD10 detector heads.
The laser unit is the heart of the RLE system, containing the
HeNe laser tube, the fibre optic launch and most of the system electronics.
Due to its fibre optic launch method, the RLU laser unit can
be mounted remotely from the precision motion stage thereby eliminating a
potential heat source without any increased demands on alignment
stability. This ensures reliable
operation.
The position output from the RLU is directly available in
differential digital RS422 format and/or 1 Vpp analogue sine/cosine
formats. From the digital output,
resolutions to 10 nm are available. The
signal period for the analogue output is 158 nm when using a double pass plane
mirror or differential interferometer, and 316 nm for a single pass
retroreflector based system. Optionally,
the RPI20 parallel interface can be used in combination with the analogue
output to provide resolutions to 38.6 picometres.
Two RLU models, referred to as RLU10 and RLU20, are available
with frequency specifications of ±50 ppb and ±2 ppb over one hour
respectively. Accordingly, the system is
referred to as either RLE10 or RLE20.
(RLE10 systems incorporate an RLU10, RLE20 systems an RLU20.)
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 - utilizing 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 lengths
|
3 m or 6 m*
|
|
Number of axes
|
Single or dual*
|
|
Laser source
|
Class 2 HeNe
|
|
Outputs
|
Analogue / digital quadrature
|
|
Velocities
|
Up 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, utilizing 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 - utilizing 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 lengths
|
3 m only*
|
|
Number of axes
|
Single or dual*
|
|
Laser source
|
Class 2 HeNe
|
|
Outputs
|
Analogue / digital
|
|
Velocities
|
Up 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.