The continuing growth in the research and development of high power diode-pumped fibre lasers relates to the exceptional thermal management provided by the extended geometry of the fibre and the small quantum defect associated with the 1 μm emitting Yb3+ ion. Lengthening the emission wavelength of diode-pumped fibre lasers further into the infrared is important for many applications ranging from medicine to defence; however, extending the emission wavelength remains a challenge. This review will examine in detail the spectroscopy and the energy transfer processes that impact Tm3+-doped and Ho3+-doped silicate glasses that are used for fibre lasers in the 1.9 μm to 2.1μm region of the shortwave infrared spectrum. We will explore a number of important applications that function in the shortwave infrared region that will benefit from using these light sources and I will suggest the reasons for choosing silicate glass over other glasses as the host material for this wavelength range. A Tm3+-doped aluminosilicate glass in a glass-working lathe in the process of being collapsed into a preform ready for drawing into double clad optical fibre. The red glow that can be observed in the centre of the preform is the thermoluminescence from the Tm3+ ions being heated to approximately 2000 °C.