A method of measuring the spatial profile of high energy laser beams with constant temporal characteristics is presented. The Air Force Weapons Laboratory (AFWL) developed this method, known as the 'Target Plate', to measure the irradiance of a near-field laser beam at any given point to assist in the assessment of material effects and system vulnerability to lasers. The Target Plate has been used to measure irradiances of 50 w/cm2 to 912 kW/cm2 on many lasers and a short wavelength arc heater. Software developed for the Target Plate can produce three-dimensional views of the beam along with data files that describe the beam as a set of irradiances versus X-Y coord-inates. This has made the technique useful for incorporating laser beam data into material damage models and optic train heating analysis.

Diagnostic requirements For the Excimer Raman-Shifted Laser Device (EMRLD) Master Oscillator (MO) demonstration test are presented. Descriptions of the instruments and their functional application are described in terms of modular configurations. Finally, an optical layout of the total system is presented.

The beam diagnostic system used: at the High Energy Laser Systems Test Facility (HELSTF) at White Sands Missile Range (WSMR), New Mexico is presented. A brief description of the instrumentation and sampling techniques used for continuous wave (CW) deuterium fluoride (OF) lasers is discussed:. Finally an optical layout is presented: showing the existing system.

The Rockwell Wavefront Analyzer (RWA) is an integrated beam diagnostic tool developed for the US Army, STEWS, WSMR, for the MIRACL device. It accepts a 2.5 cm square nominally collimated DF laser beam input of approximately 5 W power level. The electrical signals are reduced and analyzed by an on-line computer processor. The ultimate outputs are plots including total beam power and angular jitter in the x and y axes, an irradiance map of the beam on a 32 X 32 square grid, and a wavefront map of the beam on the same grid. Wavefront aberration poly-nomial coefficient listings are also generated. The wavefront is obtained from measurements of its local slope in two axes by means of a classical Hartmann test done by scanning the pupil with holes in a rotating drum. Earlier versions of this instrument we called SHAPE, for Scanning Hartmann Analyzer Plate Experiment. This design would be SHAPE IV. A single indium antimonide photopot detector measures the transverse ray aberrations, which are then subjected to elaborate processing to extract the polynomial wavefront coefficients. Another photopot is the jitter sensor. Each photopot measures power to normalize the X and Y signals; these "Z" signals also provide the beam power and local irradiance signals.

The optical diagnostics for a CW iodine laser system are presented. The iodine laser consisted of a supersonic flow gain generator and a unstable ring resonator with a rotation that produced a high quality output without an obscuration. The diagnostics subsystem was designed, assembled, characterized and integrated by a team of fourteen co-workers. The diagnostics measured the average output power, and the forward and reverse mode intensity fluctuations during the one to two second lasing time. Also recorded as a function of time was the far field beam quality, the near field intensity, the near field phase, the polarization state Stokes parameters, and the cavity longitudinal mode beat frequencies. A brief description of the resonator and its expected properties will be presented. This will be followed by a discussion of the requirements for and capabilities of the diagnostics. Included will be data reduction and analysis timeline. Next, detailed descriptions of the beam quality and polarization state measurement diagnostics will be given. Finally, examples of typical diagnostic data will be shown.

A cryogenically cooled, silicon on sapphire, electrically calibrated bolometer has been designed and measured to have a noise equivalent power of 3 x 10^-11 watt per root hertz. The electrical calibration of the bolometer has agreed with an electrically calibrated pyroelectric to better than 1 percent.

A detector system capable of measuring the waveform of pulses used to calibrate laser receivers at 1.06 μm is described. The risetime of the system is 0.8 ns. All parts of the system are available commercially. Also described is an optical impulse generator at 1.06 μm with a risetime of less than 100 ps. This impulse generator can be used to measure the impulse response of the detector system and laser receivers.

The National Bureau of Standards (NBS) maintains a set of electrically calibrated calorimeters designed and built specifically for laser energy measurements. These calorimeters are used as national reference standards for the calibration of optical power and energy meters. NBS offers laser measurement services based on the standard calorimeters to the public at a variety of laser wavelengths and power ranges. The uncertainties associated with these measurements have recently been re-evaluated.

A discussion is presented of issues specific to the measurement of pulsed ultraviolet excimer laser radiation, emphasizing a need for the establishment of standards for pulse energy, average power, and beam dimensions.

The importance of knowing the size and distribution of light within optical beams has given rise to identifying techniques and equipment that enable quantification of spatial characteristics to a repeatable and believable degree. The difficulty arises in confronting the nature of advancing technology in the design of optical systems and its impact on the equipment's need for sensitivity to various wavelengths, light levels, and beam diameters. What will be described is the development of an instrument that addresses the need for characterizing spatial properties of a wide range of optical beams at any point within an optical train. Reasoning on the sampling technique employed and the selection criteria used in designating appropriate components in order to achieve a high level of measurement accuracy will be discussed. In addition, the discussion will review the practical application of such equipment in a variety of optical system configurations.

Simple but effective means for displaying and analyzing the two-dimensional intensity distribution across UV laser beams using a plate of UV-activated fluorescent material as a key component have been developed. Applications to beam viewing, near real time intensity profilometry and quantitative diagnostics of laser beam quality are described and typical results presented.

Calibration of a Coherent Radiation Model 213 laser power sensor is reviewed. The calibration chain is traced from the National Bureau of Standards (NBS) through transfer calibrations to a working sensor. Uncertainty components in this chain, including those for use conditions, are combined to give a root-sum-square uncertainty of 7% for use of this device.

Diamond-turned optics supply the experimenter with complex shapes that can be used in a variety of optical systems. The combination of such elements can lead to very compact and lightweight collimators. Such collimators can in principle have large input apertures and long equivalent focal lengths in small packaging envelopes. This is both important and desirable where laser performance in the farfield is concerned. Based on previous tests with diamond-turned collimators, the nature of the surface errors and degree of coherence of laser light are key items.1 It is the intent of this paper to compare the farfield beam divergence of a collimated laser beam measured with a diamond-tuned collimator to the farfield beam divergence measured with a high quality glass parabola.

Entire optical benches can now be put together utilizing diamond-turned optical compo-nents. Such diagnostic systems are used for FLIR-to-laser boresight measurement, FLIR test, and TV test. These systems even have reference flats at various points in the system to facilitate automatic reference boresight alignment. There are also applications where far-field performance of laser systems is imperative, such as laser rangefinder/designators and countermeasure systems. It is the intent of this paper to compare the farfield beam divergence and spatial profile of a collimated laser beam measured with a compact diamond-turned collimator to the farfield beam divergence and spatial profile measured with a high quality glass parabolic mirror.