Goodwill as of June 30, 2020 and 2019 and changes in the carrying amount of goodwill for the respective periods are as follows (in thousands):

	As of June 30,
	2020			2019
Balance at the beginning of the period	$	57,770		$	57,855
Currency translation		(53	)		(85	)
Balance at the end of the period	$	57,717		$	57,770

In fiscal 2020, the Company performed its annual goodwill impairment test and determined that there was no impairment to goodwill. In addition, during the third and fourth quarters of fiscal year 2020, the Company reviewed for possible triggering events due to circumstances surrounding the COVID-19 pandemic and no impairment loss was recorded as a result of such review. The Company will continue to monitor its recorded goodwill for indicators of impairment.

The Company’s intangible assets associated with purchased patent license are as follows (in thousands):

		As of June 30, 2020							As of June 30, 2019
	Useful Lives	Gross Carrying Amount		Accumulated Amortization			Net Amount		Gross Carrying Amount		Accumulated Amortization			Net Amount
	(in years)
Patent license	2 - 7	$	1,170	$	(507	)	$	663	$	1,000	$	(321	)	$	679

During fiscal 2017, the Company purchased a patent license with a useful life of seven years. During the quarter ending March 31, 2020 the Company purchased a patent license for $170 thousand with a useful life of two years. The Company did not identify any triggering events that would indicate potential impairment of its definite‑lived intangible and long‑lived assets as of June 30, 2020 and 2019.

Amortization expense related to purchased intangible assets was $0.2 million, $0.1 million and $0.1 million for the years ended June 30, 2020, 2019 and 2018, respectively.

The estimated future amortization expense of purchased intangible assets as of June 30, 2020 is as follows (in thousands):

Year Ending June 30,	Amount
2021	$	228
2022		185
2023		143
2024		107
	$	663