Reduction of Temperature Sensitivity of Laser Di
ode by Using Thermal Stress Induced Heatsink
We have reduced 50% of thermal drift of wavelngth of la ser diode by using ther mal stress in duced heatsink. This heatsink improved tem per a ture sen si tiv i ty of thresh old cur rent and dif fer en tial efficiency.
Temperature affect lasing wavelength and threshold current of laser diode
Princple
Thermal Strain changes the band structure of a laser diode, and distorted band structure shifts the las ing wavelength and the thresh old current of the laser diode.
Redudce the temperature sensitivity of char ac ter is tic of laser diode
Compensation heatsink by using thermal stress
(a)
(b)
(a)
(b)
(c)
Fig.2:Compensation heatsink:coeficient of thermal ex pan sion of Zn is 30.5 (ppm/℃) , that of Invar is 1.1 (ppm/℃). (a) Laser diode strains when tem per a ture raise. (b)The cop per submount is seperated under the ridge of laser di ode. The ridge of the la ser diode be come a sin gu lar point of stress. (c) picture of laser diode mod ule.
(c)
(d)
Fig. 1: Temperature dependency of I-L curve and spectrum: (a) I-L curve of a laser diode installed on a copper heatsink. (b) Spectrum of a laser diode in stalled on acopper heatsink (c) I-L curve of a laser diode installed on a compensation heatsink (d) Spectrum of a laser diode in stalled on a compensation heatsink