Ophir-Spiricon - Beam Profiler

In addition to the stackable filters and beam splitters described above, one can purchase the LBS-100 system that is not as compact as the stackable system above but has larger aperture, can be changed without disassembly and has versions for longer wavelengths. The system contains the mounting frame, 1 wedge beam splitter and several attenuators. The exit end of the LBS-100 is standard C mount thread so all our cameras can be mounted to the frame. The wedge angle is 6.5 degrees to insure that the reflection from the rear side will not enter the camera. The optical elements are flat to 1/4 wave in the visible to insure no distortion of the beam.

Description

Specifications

Ordering Info

Catalog/Manual

Download Data Sheet.

Integral Beam Sampler and Attenuator

The models LBS-100, LBS-100YAG, and LBS-100IR Laser Beam Sampler/Attenuators, shown in Figure 1, are designed to be utilized as integral components of the LBA-PC series Laser Beam Analyzer and Pyrocam III systems. Capable of right-hand, left-hand, or vertical beam sampling and wide dynamic range, the LBS-100, LBS-100YAG, and LBS-100IR minimize diagnostic setup time and facilitate in-situ laser beam analysis of pulsed and CW applications.

Figure 1. Mechanical drawing of LBS-100 Beam Samplers.

A slip-ring collar with locking setscrew permits the Laser Beam Sampler to be interfaced with a C-mount camera at any angle of rotation. A non-marking thumb screw secures the wedge in place.

Beam Sampling

The LBS-100 has an uncoated 6.5° Quartz wedge that intercepts the laser beam at 45° and diverts approximately 4% of the beam power/energy through the neutral density filters to the video camera. Approximately 92% of the laser beam is transmitted to the experiment target. The transmitted beam is deflected approximately 4.5° from the original path. It is diverging an additional 5° in the axis of the wedge. The LBS-100YAG consists of a quartz wedge A/R coated for 1% reflection of both S and P polarizations at 1064nm. This provides accurate analysis of any YAG laser by providing equal S and P reflection. (For multiple wavelength applications where the beam polarization is critical we recommend the Beam Tap II in combination with the BA Series Attenuators.)

The LBS-100IR has a 6.5° ZnSe wedge coated for minimum reflection at 10.6µm. One version diverts 0.5% (± 0.15%) of the beam to the camera. The other version diverts approximately 5% of the beam. Order the 0.5% reflecting wedge for laser power up to 1kW, and the 5% wedge for laser power up to 100W. From 9µm to 11µm the reflection of both versions increases about 40% above the value at 10.6µm. The transmitted beam is deflected by the wedge from the original path by about 11°. The reflection vs. wavelength of the 0.5% AR coated wedge is shown in Figure 6. The reflection spectrum of the 5% version is similar.

Beam Attenuation

For additional attenuation after beam sampling the LBS-100 and LBS-100YAG use bulk absorbing ND filters. The filters supplied for the LBS-100 and LBS-100YAG come in a set of 6 each 2" X 2" filters, with ND number and transmission shown in Table 1.

ND VALUE	TRANSMISSION
0.3	50%
0.7	20%
1.0	10%
2.0	1%
3.0	0.1%
4.0	0.01%

Table 1 - ND Filter Set Values for LBS-100 and LBS-100YAG.

Figure 2. Transmission vs. wavelength for LBS-100 bulk absorbing filters using a linear scale.

The wavelength response of the filters is shown in Figures 2 to 3. The LBS-100 filters of Figures 2 and 3 are calibrated at 546nm, and give fairly uniform attenuation from 400nm to 700nm. While they attenuate from 351nm to 400nm and from 700nm to 2600nm, the stated calibration steps can be much different for these wavelength ranges. The ND filters for the LBS-100YAG are calibrated specifically at 1064nm.

Figure 3. Transmission vs. wavelength for LBS-100 bulk absorbing filters using a logarithmic scale.

A set of CaF₂ flats is used in the LBS-100IR for further attenuation. It consists of 4 pieces. Three pieces are 3mm thick and provide about 30% transmission at 10.6µm, or ND = 0.5. The fourth piece is 1mm thick and provides 65% transmission at 10.6µm or ND = 0.2. Figure 4 shows the transmission vs. wavelength of CaF₂ in 1mm and 3mm thickness.

Figure 4. Transmission vs. wavelength of CaF₂.

Figure 5. AR coated ZnSe wedge typical reflection curves for S and P polarization.

Figure 6. Maximum power input to wedge versus beam size

Performance Specifications

Characteristic	LBS-100	LBS-100YAG	LBS-100IR
Optical wedge material	Quartz	Quartz	ZnSe
Wedge angle	6.5°	6.5°	6.5°
Wavelength range
Recommended	400nm-700nm	1064nm	10.6µm
Functional	400nm-2600nm	400nm-2600nm	9µm to 11µm
Wedge A/R coating reflection	Uncoated	1% @ 1064nm	0.5% or 5% @10.6µm
Through beam deflection angle	4.5°	4.5°	10.7°
Through beam added divergence	≈5°	≈5°	≈5°
Clear aperture	.9 inch	.9 inch	.9 inch
Damage input power to wedge*(see fig. 6)	100W/cm²	500W/cm²	1000W for R = 0.5% 100W for R = 5%
Damage input energy to wedge*	6kJ/cm² (1ms pulse)	30kJ/cm² (1ms Pulse)	10⁵J/cm² for R = 0.5% 10⁴J/cm² for R = 5%
Damage input power to ND filters*	5W/cm²	5W/cm²	5W/cm²
Damage input energy to ND filters*	300J/cm² (1ms pulse)	300J/cm² (1ms pulse)	300J/cm² (1ms pulse)
Surface quality - wedge
Scratch/Dig	60/40	60/40	60/40
Flatness @632.8nm	λ/4	λ/4	λ/4
Surface quality - ND filters
Scratch/dig	80/50	80/50	80/50
Flatness @632.8nm	λ/4	λ/4	2λ
Parallelism	<2 arc min	<2 arc min	<3 arc min
Mounting	1/4"-20	1/4"-20	1/4"-20
Weight with wedge and filters	24oz	24oz	24oz

Notes: *Maximum recommended power or energy is about 10% of damage to avoid thermal lensing. Typical damage threshold of a CCD camera sensor is approximately 1.5 X 10^-4W/cm² and 1.0 X 10^-3J/cm². Typical saturation level of a CCD camera sensor is approximately 3X10^-7W/cm² and 4X10^-9J/cm² Exposure to laser power/energy levels greater than the damage values listed here may cause permanent damage to the ND filter materials, which may also result in permanent damage to the camera.

	Item	P/N

	LBS-100	SP90061

	LBS-100 YAG	SP90057

	LBS-100IR 0.5	SP90058

	LBS-100IR 5.0	SP90059

	LBS-100 to 4X bem reducer adapter	SPZ17029

		Beam Profilers Catalog 107 pages (8.12 MB )
		LBS-100 user notes 4 pages (680 KB )