We report on a systematic study of the laser threshold and slope efficiency of solid-state dye lasers operating in the near-infrared under µs pumping. The excitation source for this work is a flashlamp-pumped dye laser operating at a wavelength of ≅660 nm with a pulse duration of ≅1.25 µs. A major objective of this work is to demonstrate laser characteristics traceable to direct diode-pumping of a dye-doped solid matrix. Detailed measurements were made for three laser dyes and three different host materials. Dyes evaluated include Rhodamine 700, Rhodamine 800 and Oxazine 725 at various concentrations. The host matrices studied were modified PMMA (MPMMA), polymer-filled nanoporous glass (PFNPG), and organically modified silicate (ormosil). Laser measurements included output energy and wavelength as functions of input energy and resonator feedback (Roc). Findlay-Clay analyses were performed to extract information on the round-trip cavity losses in each case. Temporal waveforms were obtained for the pump and output pulses in order to evaluate the extent of tracking, and to study the mechanisms for loss of tracking. The highest laser efficiency observed was 43% for Oxazine 725 (1.2 × 10^-4 M) in MPMMA for a 2-mm thick sample. This material had a laser wavelength of ≅690 nm for Roc < 0.70. The value increased to ≅735 nm, however, for R > 0.80. The longest output wavelength observed in this study was ≅797 nm for Rhodamine 800 (6.0 × 10^-4 M) in PFNPG. The highest efficiency observed for this particular sample was 21%. Its emission wavelength was relatively insensitive to feedback over the range studied (0.30 < Roc < 0.95). Measurements of laser threshold are presented and discussed for the materials investigated.